TClassAttributeMap for properties

(cherry picked from commit 45fa0d94ca9e70cc7d25405f236dcdc96b0b89d5)
TClassAttributeMap property

(cherry picked from commit 25523518ef1b05cbbe507f01cd6dfea261434a36)
Add TClassAttributeMap.

(cherry picked from commit 17ba27b1ddbc64b8c7a7695f895caf3af0c56545)
Fix compiler warnings (hidden overridden Clear(), missing return.

(cherry picked from commit 362219a30cce0c893224a563cddad5e73d4b6ba6)
Fix TClassAttributeMap and TClass

(cherry picked from commit e7ac2407e734f4f174fe378432cc62d141b70eae)
Apply relevant parts of c42b215595a fom master.
Add missing initialization
Synchronize test/stressProof.cxx with the master version
Add missing protection to avoid reading before the start a string.

This fixes ROOT-5353.
Function to Print() any TObject on PROOF cluster
Synchronize ProofNtuple from master (needed by stress test multi-trees
Check for a potential NULL return (Coverity 51911)
Fixed xpd.stagereqrepo directive support in PROOF
Safer use of Form() with a TString buffer
Invalidate processing if init of TTreeFormulaManager fails
Add switch '-k' to force keeping all log files
PROOF user cfg always overrides cluster-wide setup
In TDSet::SetObjName, propagate the name to the elements
Remove unnecessary call to TDSet::SetObjName
In TASImage::DrawtText, TTF::SetTextSize was called with a rounded value (to pixel). This cause some misplacements of character in TLatex formulae.