Minor changes required for Mac OSX10.10 (Yosemite)
Fix for ROOT-6836 (make build fails on Yosemite)
Fix register warning.
Align compiler and options with master
Increase version number to avoid spurious warning.

The warning happens when reading a new file (v5.34/21) in an older version of ROOT (v5.32 for example)
(i.e. forward compatibility).  The Warning is due to the typedef now be stripped away in checksum
calculation.
Run stressTMVA in batch mode (fixes headless cocoa).

(cherry picked from commit 9f6cdc8fd819464b2dca4d235bd79690c799149b)
Always delete the array when the array size goes down to zero.

This fixes a problem seen by CMS when using TH1::Copy on histograms read
from a TTree.

This amend commit d31f38f98c66af492c20c3bf060df13d64c465f0 (circa 2005)
- Sometimes an extra point appeared in the center of a TGraph2D plot (when drawn with markers)
  The problem was mentioned here: http://root.cern.ch/phpBB3/viewtopic.php?f=3&t=18787&start=15
- Better manage the attributes reset when going from a markers representation to an other (P, P0, PCOL).
The hollow fill style was not rendered correctly (https://sft.its.cern.ch/jira/browse/ROOT-6841)
Disable Vc warnings on Windows.
Add protections at zoom limits.
Add missing lock to  TDataMember::Property
Add missing lock in TClass::IgnoreTObjectStreamer

Conflicts:
	core/meta/src/TClass.cxx
Remove obsolete code
For debugging make 'error' fatal
Avoid unnecessary recursion of BuildOld (and co) for emulated class
Add comment on suspicious (thread-safety wise) part of the code

Conflicts:
	io/io/src/TBufferFile.cxx
make error fatal for debugging
Extend reach of error message
Remove (now) redundant (useless) work.

IsCompiled() means that Build() or BuildOld() has been called.