Use PartialF for Int type.

Minor performance degradation.
Causes some sketch benchmarks to stop working.
Use an IntMap for symbolic ints.

Makes a huge difference for some sketch tests.
Other times it slows things down a little.
Implement Smten.Data.Map.member function.
Switch to later version of STP.

Needed in preparation for switch to ghc7.8, which needs STP to be built as a
shared library.

This should work with any version of STP after February 10, 2014.
Specifically after STP revision 792cbc07982da3f08853a61db680cbfe9bf4ee6a.
Implement Smten.Data.Map.member function.
Merge branch 'symint'
Manually merge code from ghc7.8 branch for better cast generation.
We only need one typeCG function.

Not typeCG, topTypeCG, castInnerTypeCG, and castOuterTypeCG.