Implementation of isalnum, isalpha, isdigit, islower, isspace, istitle and isupper
Code cleanup, fixes after CR
Implemented dict.__len__
Factor out tupleGetitemInt.
Add tupleGetitemSlice.
Raise TypeError when slice type is not understood.
Fix formatting.
Merge branch 'str_iseverything' of https://github.com/kkszysiu/pyston

Merges PR #109
Merge branch 'dict_len' of https://github.com/kkszysiu/pyston
Merge branch 'enh-tuple-getitem' of https://github.com/jvkersch/pyston
Some Makefile changes for compiling extension modules

Some tweaks to better support C (as opposed to C++) compilation.
Can now compile extension modules using gcc, in addition to clang as before.
Support for __get__ and __set__ for descriptors