Log Message:
Update to Yap 6.2.2

In terms of the core YAP, most changes are small bug fixes. They include

- better support for 64 bits in win64,
- some fixes to the garbage collector
- OSX Lion compilation
- wide char support
- bug in copy_term when some variables have attributes
- fixes to lam interface
- C-interface and SWI support
- over-optimisation of =/2.
- arithmetic exceptions
- write_canonical (Ulrich)
- retracting may not follow lu semantics
- minor predicate import bug.

There has been a lot of progress in ProbLog and cplint.