Fix test suite for Windows

This PR contains 2 things:
* An improved regexp escaping using code from Closure Library
* A fix for test suites to work on Windows (tested on Windows 7 & Node v0.8.14). I fixed the `require()` and the line breaks in Italian stemmer tests.

Before merging, please make sure the test is passing on Linux or Mac. I can't test under these OS at the moment.