Python bindings

Python bindings

Python 2.6 is unsupported because the PyCapsule API was backported from Python 3 to 2.7. Trying Python 3.3 and 3.2 just for grins.

Conflicts:
	src/bindings/python/SConscript
	src/bindings/python/hammer_tests.py
	src/bindings/swig/hammer.i
	src/hammer.h
	src/parsers/choice.c
	src/parsers/sequence.c

Conflicts:
	src/bindings/python/SConscript
	src/bindings/python/hammer_tests.py
	src/bindings/swig/hammer.i
	src/hammer.h

Cleaned up python bindings interface a bit; now returns strings rather than character codes if appropriate

kindasorta working. all tests (except h_action and h_attr_bool, need typemaps) have passed at one time or another, but some segfault at not-quite-random; h_and, h_epsilon_p, h_end_p, h_ignore, h_not, maybe h_choice seem culprity.

h_sequence, h_choice and HCountedSequence are all having weird issues, but tests are in a workable format now

There's a typemap problem between const uint8_t* and target-language strings, but I can create parsers in python and php.

Import combinator and allocator APIs into SWIG. Next is glue. Need to fix unions in HParsedToken and HCaseResult.

 * "in_" and "not_in" should coerce their results to strings (i.e., chr(result))
 * TestLeftrec: success case 2 fails
 * TestChRange: success case segfaults
 * TestWhitespaceEnd: success case segfaults
 * TestAction: success case segfaults with "corrupted double-linked list"
 * TestButNotRange: segfaults, probably because of whatever's wrong with ch_range
 * TestXor: segfaults; failure case craps out with "malloc(): smallbin double linked list corrupted"