Fix long64 issues in ROOT 6 Conditions code

Many (102) relvals in ROOT6 fail in the conditons code because of a name mismatch between "(unsigned) long long", used by Reflex and the Conditons database, and "(U)Long64_t", used by ROOT.  I have fixed a few of these before, but they keep cropping up.  So,this pull request is a comprehensive fix for these issues, once and for all.  It adds a new member function to TypeWithDict that will return "long long" as the name, rather than "Long64_t", and changes the conditions code to use this new function 
Note:  because of the new member function, this request causes 829 packages to rebuild.
The only header change is a new function declaration.  No existing interfaces were changed.
Please merge this promptly, so I won't have to keep rebuilding 829 packages.
Note: With this fix, the 102 tests still fail, but later for a different reason.  The next failure is a segfault,
but this request should still be merged.