Use bitfield for transient bool
In FindObject, return without calling GetClassInfo if we can
Add future warning for debugging
Prepare for the root-pcm and delayed header parsing.

Add the flags:

   fHasRootPcmInfo   : Whether info was loaded from a root pcm.
   fCanLoadClassInfo : Indicates whether the ClassInfo is supposed to be available.

and getters:

   HasDataMemberInfo  : Whether the class knows about its (compiled) data member
   HasInterpreterInfo : Whether the ClassInfo is available.
   HasInterpreterInfoInMemory : Whether the interpreter information about the
      class has been loaded in the interpreter _and_ connected to the TClass.
Avoid calling GetClassInfo when we do not need to actual get a hold of the interpreter information