* Rename mch_FullName to mch_full_name to match the style guide.
* Add mch_full_dir_name, which saves the absolute path of a given
directory relative to cwd into a given buffer.
* Add function append_path, which glues together two given paths with a
slash.
* Adapt moonscript coding style to the tests.
Tests will be written using the [moonscript](http://moonscript.org/) language,
a lua 'dialect' that is whitespace-significant and has a syntax similar to
coffeescript. The test framework used is [busted](http://olivinelabs.com/busted/),
a bdd framework for lua/moonscript.
Luajit has a nice ffi module, which lets lua programs link shared libraries and
call it's functions without writing any C code.
To take advantage of this fact for testing C functions, a new target was added
to CMakeLists.txt, which compiles neovim as a shared library that is loaded by
the process running the tests.
This commit adds necessary code for downloading and installing a lua package
manager(luarocks) locally. It wasn't added as a subtree because there are quite
a few blobs in its source tree.
