Trigger travis-ci build
Adds travis-ci status image to README.md
Changes submodule back to local libsass version
Removes dependency from File::Slurp
Removes test case due to upstream regression

https://github.com/sass/libsass/issues/364
Trigger travis-ci build
Adds coveralls.io to travis-ci configuration
Adds more test cases for pseudo selectors

To distinguish correctly between indented sass
properties (prefixed by colon) and pseudo selectors.
Adds more advanced pseudo selector test
Adds test cases for file interface (OO and procedural)
Updates libsass module to latest local version
Fixes test cases for perl 5.10
Forces unix line feeds for test files
Testing libsass code coverage