Add return value to ann2fig.cpp main function

Required for it to compile under Apple's g++.
Remove env fiddling from setup.py.
Adding some generated/compiled files to .gitignore.
Patch sparse_hash to get it working on Mavericks

Patch copied from https://code.google.com/p/sparsehash/issues/detail?id=99.
Fix clean target in ann_1.1.2/Makefile.
Clean up formatting in setup.py.
Add more things to .gitignore.
Use pyaccess as the package name.
ifdef out some DLLExport stuff so it only shows up on Windows.
Merge pull request #1 from jiffyclub/master

Compile libraries under clang on Mac