[Doc] improve TStatistic documentation

On my systems (RHEL7 and Android Termux) PAGE_SIZE is defined to 4096 in /usr/include/sys/user.h .  The enum then produces a compile-term error.
Adding this change resolves this error for me.

This patch fixes an assertion in the incremental builds.

the code becomes more readable than before without loosing any
coverage.

This is done by taking the check of fUniqueID and the assignment to fBuits
into a separate function and by including this function in the header
*but* marking it as "noinline" to prevent its inlining and preserve a
way to suppress the valgrind warning.

Introducing the macro R__NEVER_INLINE which expands to

   inline __attribute__((noinline))

The performance degradation is less than 10% for a case doing
only creation and destruction of TObjects.

See https://root-forum.cern.ch/t/ttree-setalias-with-tmath-min-tmath-max-issue/33881.

dataframe_nodes.cxx(97): error C3493: 'nBinsExpected' cannot be
implicitly captured because no default capture mode has been specified

This reverts commit 4846a973.

This reverts commit ff376578.

This reverts commit 9e38c890.

since this prevents the correct transformation to notebook.

Locking on a child view while inside the parent's -drawRect:
was always looking horrendously (alas, this is how ROOT text
rendering is implemented in TGTextView et al.). Finally,
with macOS 10.14 released, after all these years of horrors, it
stopped  working at all. While it's still quite crappy that
TGTextView tries to render text in its child window - TGViewFrame
- it does not mean literally we physically have to do this. A
little cheat and we render in the correct view instead.

Fixed by a2950e2dfa

It should be capable to work with ROOT6 and ROOT7 classes

Simplify range selection - exclude button

When significant changes are performed, model send to server and
updated. If changes has effect on other parameters, changed model
version send to the client back.

This is can be implemented on the server side, make no big sense now
Cleanup code

Instead of separate dialog parameters show in extra tab.
Every time new model is selected correspondent parameters are fetched.
Also when fit is performed, result parameters are shown

Replace all by Grid, one still can have responsive changes if one wants
them

Such tab can be invisible by default, but enabled later.

Also use Grid layout with individual spanning parameters

Should be much easier to handle

Avoid use of ui5 Form pattern - it does not allow to use really compact
design and does not allow to use any kind of layout inside.

View is not that flexible (as Form pattern only promise) but much more
predictable!

Introduce special class for function info - it can include more info
than abstract combo-box item

Now more clear member names are used and function name use direct for
selection

* Use gDirectory and fHist provided to fitpanel. 
* Use string identifiers with hsitogram names
* Extract list of available TF1 objects, let sort them (do it by UI5?)
* Use std::string_literals where it make scence
* Use more compact c++11 intializer for large vectors