Related issues: ROOT-10127, ROOT-10138

fPool should be used in Form() when it's not null,
not the reverse.

Related issues: ROOT-10127, ROOT-10138

Can cause unnecessary extra linking to system libraries. We should
add linking libraries directly to each target that needs it.

XrdSecEntity::Reset() is only available in newer versions of XRootD.

ROOT-9595 #close

by avoiding linear search (caching when needed, passing known information when available)

In case of VariableTransform.cxx, reformatted the whole file as it was
using 4 whitespaces indentation and had misleading indentation on the
bottom.

Deprecated in v6.14; plan to remove in v6.16

[net/monalisa/src/TMonaLisaWriter.cxx:956] -> [net/monalisa/src/TMonaLisaWriter.cxx:957]: (error) Iterator 'iter' used after element has been erased.
[proof/proofd/src/XrdProofdProofServMgr.cxx:4648] -> [proof/proofd/src/XrdProofdProofServMgr.cxx:4646]: (error) Iterator 'iter' used after element has been erased.

[math/minuit2/src/Minuit2Minimizer.cxx:669] -> [math/minuit2/src/Minuit2Minimizer.cxx:669]: (style) Same expression on both sides of '||'.
[math/minuit2/src/Minuit2Minimizer.cxx:736] -> [math/minuit2/src/Minuit2Minimizer.cxx:736]: (style) Same expression on both sides of '||'.
[math/minuit2/src/Minuit2Minimizer.cxx:753] -> [math/minuit2/src/Minuit2Minimizer.cxx:753]: (style) Same expression on both sides of '||'.

[tree/tree/src/TBasket.cxx:852]: (style) Redundant condition: If 'flag >= 80', the comparison 'flag' is always true.
[misc/table/src/TFileIter.cxx:467] -> [misc/table/src/TFileIter.cxx:468]: (warning) Identical condition 'thisRunNumber<runNumber', second condition is always false

[math/mathcore/src/TMath.cxx:826]: (style) Array index 'ia' is used before limits check.
[math/mathcore/src/TMath.cxx:830]: (style) Array index 'ib' is used before limits check.
[math/mathcore/src/triangle.c:15434]: (style) Array index 'aspectindex' is used before limits check.
[roofit/roofit/src/RooIntegralMorph.cxx:375]: (style) Array index 'igapHigh' is used before limits check.

[core/winnt/src/TWinNTSystem.cxx:5035]: (style) Statements following return, break, continue, goto or throw will never be executed.
[tree/treeplayer/src/TSelectorDraw.cxx:380]: (style) Statements following return, break, continue, goto or throw will never be executed.

[net/auth/src/TAuthenticate.cxx:4205]: (error) Resource leak: fd
[roofit/roofitcore/src/BidirMMapPipe.cxx:1880]: (error) Memory leak: s
[tree/tree/src/TLeaf.cxx:222]: (error) Memory leak: countname
[tree/tree/src/TLeaf.cxx:226]: (error) Memory leak: countname
[tmva/tmva/src/MethodBase.cxx:2783]: (error) Memory leak: pdfS
[tmva/tmva/src/MethodBase.cxx:2783]: (error) Memory leak: pdfB

[roofit/roofitcore/src/RooAbsArg.cxx:280]: (style) Redundant checking of STL container element existence before removing it.

[core/dictgen/src/rootcling_impl.cxx:457]: (performance) Possible inefficient checking for 'fieldSelRules' emptiness.
[core/dictgen/src/rootcling_impl.cxx:4573]: (performance) Possible inefficient checking for 'filesIncludedByLinkdef' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:322]: (performance) Possible inefficient checking for 'fWebConn' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:374]: (performance) Possible inefficient checking for 'fCmds' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:419]: (performance) Possible inefficient checking for 'fWebConn' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:475]: (performance) Possible inefficient checking for 'fWebConn' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:587]: (performance) Possible inefficient checking for 'fCmds' emptiness.
[gui/canvaspainter/v7/src/TCanvasPainter.cxx:787]: (performance) Possible inefficient checking for 'fCmds' emptiness.
[html/src/TDocParser.cxx:684]: (performance) Possible inefficient checking for 'currentType' emptiness.
[proof/proofd/src/XrdProofdManager.cxx:804]: (performance) Possible inefficient checking for 'uwrks' emptiness.
[proof/proofd/src/XrdProofdSandbox.cxx:467]: (performance) Possible inefficient checking for 'staglst' emptiness.
[proof/proofd/src/XrdProofdSandbox.cxx:571]: (performance) Possible inefficient checking for 'actln' emptiness.
[roofit/roofitcore/src/RooSimWSTool.cxx:574]: (performance) Possible inefficient checking for 'slist' emptiness.

all the reports Prefer prefix ++/-- operators for non-primitive types

Called in TDSet::SetEntryList fixes ROOT-8165 .

Fix mostly warning C4138: '*/' found outside of comment. But also:
warning C4101: 'hProcess': unreferenced local variable
warning C4005: 'open': macro redefinition
warning C4002: too many actual parameters for macro 'open'
warning C4091: 'static ': ignored on left of '' when no variable is declared

Error in <TStatusBitsChecker>: In TProofPlayer class hierarchy, there are duplicates bits:
Error in <TStatusBitsChecker>:    Bit  16 used in TProofPlayer as kIsProcessing
Error in <TStatusBitsChecker>:    Bit  16 used in TVirtualProofPlayer as kIsSubmerger

Error in <TStatusBitsChecker>: In TProofServ class hierarchy, there are duplicates bits:
Error in <TStatusBitsChecker>:    Bit  16 used in TProofServ as kHighMemory
Error in <TStatusBitsChecker>:    Bit  16 used in TApplication as kDefaultApplication

This refactors the CMake build files to no longer manually call
the CMake functions for generating and linking the dicionairies.
One reason is to reduce boilerplate, the other is that it is now
no longer possible to have naming mismatches between the dictionary
generation arguments and linking function arguments which was causing
the race conditions we had in our build system.

This also now follows more strictly the separation between dependencies
like Math, Tree and Core and pure linking flags to external libraries.

This property was renamed in CMake 2.8.12, so we now should use
the newer name on recent CMake versions. We don't need to support
the pre-2.8.12 versions of CMake because we anyway have code
that requires 3.x.