Move TProtoClass functions into TProtoClass.cxx; add TProtoRealData.

TRealData is now stored in a new structure TProtoClass::TProtoRealData.
Its list is stored as a series of these objects, separated by TObjStrings
that signal a new parent TClass for the data members. It is only reconstructed
when building the target TClass, not when reading the TProtoClass.
Use new interface to create a TProtoClass.
We can now visit abstract classes.
Do not diagnose in case of transient classes.
Must call Size(); not the same as fSizeof.
Remember that a base class is virtual and needs an object to determine the offset.
Store the offset for the streamer call.
Remember whether the pointer is a valid one, or only records the offset.
Only pass the object to BuildRealData() if the inspector has one.
Merge feature branch storing TProtoClass+TDataMember+TRealData in ROOT PCM.
Add interface to pass arguments to cling construction.
Pass interpreter arguments also to TCling-interpreter.
Pick up static cling arguments; simplifies invocation from rootcling.
Use TROOT::GetExtraInterpreterArgs() to pass arguments from rootcling to TCling.
Check for != NULL.
TGaxis::SetMaxDigits was not active on standalone TGaxis.
add a dummy test in case of 32 bits arch to have same output file
The transparency sliders change the transparency only for the currently edited object. (ROOT-6251)
Transparency
Changes to CMake to cope with the new rootPCMs (ROOT-6199)