Initially ROOT_BINARY_DIR is automatically generated by CMake and equal
CMAKE_BINARY_DIR. Next change is adjusting ROOT_BINARY_DIR used
in ROOTConfig.cmake for ROOT binaries as a ROOTBIN_DIR

Adding a deprecation for uncorrectly used ROOT_BINARY_DIR

This makes ROOT's CMake macros like ROOT_GENERATE_DICTIONARY()
readily available after a successful call to find_package(ROOT),
without having to call include(${ROOT_USE_FILE}), which will
append ROOT's compilation flags to flags of the including project,
potentially overriding them (i.e. -O3 with -O2, etc).

Incorporate the changes of this patch:

https://bitbucket.org/wlav/cppyy-backend/src/master/cling/patches/templ_ctor.diff

spell check

Typos

Fix typos

silenced after commit 466e5825

silenced after commit 466e5825

to the AddEntry function was changed according to the fact that the

None -> null pointer conversion is no longer implemented in Cppyy

If the constructor of the contained object is not run (e.g. because
assembling its arguments triggered an exception), the dtor must not
be run when destructing the cling::Value. Detect this case by imprinting
canary bytes into the contained object bytes: if they have changed,
run the dtor, if not assume that the constructor has failed.

This will cause false positives in those cases where the constructor
is not modifying the first object bytes: in these cases, the dtor
is not run even though the ctor is run. That is still better than
the other case (where the dtor crashes because no ctor was run).

Fix issue with popup (and context) menus popping up on wrong display on Windows with multiple display configuration

Now added for symmetry with surrounding code.

Remove the typo that caused "Last cluster in processed TTree is
dropped under specific circumstances".

"Last cluster in processed TTree is dropped under specific
circumstances"

* Show up with gcc9

C4005: 'NOMINMAX': macro redefinition
C4138: '*/' found outside of comment

(some) original messages:

lexertk.hpp(1017): warning C4266: 'int
lexertk::token_inserter::insert(const lexertk::token &,const
lexertk::token &,const lexertk::token &,const lexertk::token &,const
lexertk::token &,lexertk::token &)': no override available for virtual
member function from base 'lexertk::token_inserter'; function is hidden 

lexertk.hpp(1317): warning C4266: 'bool lexertk::token_scanner::operator
()(const lexertk::token &,const lexertk::token &,const lexertk::token
&,const lexertk::token &)': no override available for virtual member
function from base 'lexertk::token_scanner'; function is hidden

Here size_t variable converted into unsigned short - windows complains.
Original message:

RDFDisplay.cxx(96): warning C4267: '=': conversion from 'size_t' to
'_Ty', possible loss of data 

RDFDisplay.cxx(117): warning C4267: '=': conversion from 'size_t' to
'_Ty', possible loss of data

Original messages (all the same):
warning C4267: 'argument': conversion from 'size_t' to 'Font_t',
possible loss of data 

Original message:
TCling.cxx(7182): warning C4805: '==': unsafe mix of type 'int' and type
'bool' in operation 

Fixes warning from Travis:
```
include/TUrl.h:59:4: note: Calling default constructor for
'\''TObject'\''
   TUrl() : fUrl(), fProtocol(), fUser(), fPasswd(), fHost(), fFile(),
```   

Also use nullptr instead 0 where it makes sense