Cut in half the cost of G__store_dictposition (and thus indirectly reduce the cost of G__calc),

by removing the ptype array (a copy of G__struct.type) which was used to restored the type 
back to 'autoload' during unloading (this is now done more efficiently by G__close_inputfiles_upto)
and to count the number of new class/struct/namespace in the file.  This is replace by keeping
tracking of the actual number in G__srcfile.definedStruct, G__dictposition.nactives and in 
G__struct.nactives.


git-svn-id: http://root.cern.ch/svn/root/trunk@27122 27541ba8-7e3a-0410-8455-c3a389f83636