The state of the transaction needs to be switched to committed to signal that no new decls should be appended.
That is only needed before iterating over the decls, which only happens at the codegen part.
The transformers must be (and are) able to iterate over a transaction that gets appended to.


git-svn-id: https://root.cern.ch/svn/root/trunk@49094 27541ba8-7e3a-0410-8455-c3a389f83636
Rename state kUnknown to kCollecting.
Implement Transaction::printStructure().
Remove unnecessary non-const overload of getWrapperFD().


git-svn-id: https://root.cern.ch/svn/root/trunk@49095 27541ba8-7e3a-0410-8455-c3a389f83636
Move #include <gvc.h> from the .cxx to the .h files.
That way we are compatible with the old and new graphviz.


git-svn-id: https://root.cern.ch/svn/root/trunk@49096 27541ba8-7e3a-0410-8455-c3a389f83636