Merge pull request #51 from mattkelly/master

Resolve all compiler warnings
Fixed for Linux - pushing to test on OS X
OS X still works with pthread fix - added explanation
Merge pull request #54 from mattkelly/pthread-fix

Fix pthread compile errors on Linux
Merge pull request #52 from mattkelly/whitespace

Convert rest of source to 4-space indent
Merge remote-tracking branch 'upstream/master'