Merge pull request #14 from ethanhugg/master

Rebase of EKR's patches for tracing and frame size with makefile updates.
Add gtest support
Added
Add a trivial init test
Make gtest support conditional
Merge pull request #15 from ekr/add_gtests

Add gtests
Fix gtest detection
Merge pull request #16 from ekr/gtest_fixup2

make gtest-bootstrap will pull down gtest and then make will build the codec-unittest.
Fix issue:#9

update VS2010 and VS2012 project
fix VS build issue: can't find typedefs.h in console project
Merge pull request #18 from ruil2/master

fix VS build issue: can't find typedefs.h in console project
Fix a typo in the public codec API
Merge pull request #19 from mstorsjo/typofix

Fix a typo in the public codec API