Fix compilation issues on MacOSX 10.8.2 / XCode 4.6 CLT

Dependencies installed using homebrew:
- brew install git
- brew install cmake
- brew install boost --with-c++11
- cmake .. -DBUILD_TESTS=1
- make
Improve logging message format.

Colored FATAL errors are now using the inverted default foreground color.
- This should be nicer on black on white terminals.
Non terminal output is now formatted in JSON.
- Structured logs is always better.