Add libmarisa

libmarisa is a library that implements a static and space-efficient trie data structure.

This library is required by https://github.com/lotem/librime
The source code is not available at `test do` time  but you could add that to `install`. See `cmake.rb` for an example of an application formula with a good test and `tinyxml2.rb` for an example of a library formula with a good test. Thanks!