Fix SCons bugs

Don't clober the Environment (and thus the ENV['PATH'] by redefining it
and don't link against lr by default. Only add it if uname is not Darwin
Clean up ENV

Don't pass the entire environment to SCons. Only pass the PATH
Merge pull request #46 from jrozner/master

Fix SCons bugs
Finished writing unit tests. Fixed a few small bugs in hammer.py. Further issues:

 * "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"
Ditch longs and long longs in favor of stdint.h types, which has cascading
effects throughout, including use of inttypes.h/PRI[ud]64 because printf() is
still stuck in a long world, conversion of %lu to %zu for printing values of
type size_t, and changing/renaming the g_check_cmp* family of functions.
Merge pull request #48 from pete-/master

Ditch longs and long longs in favor of stdint.h types, which has cascadi...
Add internal conditional to not use stdarg.h for SWIG use
Merge pull request #50 from thequux/conditional-varargs-in-header

Add internal conditional to not use stdarg.h for SWIG use
Merge branch 'master' of https://github.com/UpstandingHackers/hammer into swig
Import combinator and allocator APIs into SWIG. Next is glue. Need to fix unions in HParsedToken and HCaseResult.
fixed nested unions
invoke swig with relative path instead, -I../../
SWIG bindings build, compile, and appear to work for python. Will port over tests next.
There's a typemap problem between const uint8_t* and target-language strings, but I can create parsers in python and php.
SWIG python bindings, has same typemap problem as PHP
fix travis config here too
helps to link against the library...
sync with php-bindings SConscript
typemap to fix conversion from python strings to uint8_t*
python tests baked into scons; h_ch needs the first char of its input string as its input