LESS (Fixed #346: source map path fixes & code refactoring) and Analysis (warning fixes)

CA fixes for:

- [CA1002](http://msdn.microsoft.com/en-us/library/ms182144.aspx) // unsuppressed from ruleset and fixed in code

# LESS Source Maps:

First off, there are three kinds of URLs we are dealing with:

- Path to map file in compiled CSS file.
- Path to LESS file in map file.
- Path to CSS file in map file. 

Unfortunately, there is no clear documentation and the SourceMap support in browsers is still unclear. For instance, by this thread https://github.com/less/less.js/issues/1050, one can observe:

- Chrome is the only browser supporting CSS source maps.
- Chrome 29 used to accept only absolute URLs in source maps.
- Chrome 32 supports the absolute as well as the *relative to compiled CSS* paths.

This fix (3a4950f) will devise *all the paths* from the compiled CSS file. 

Since I haven't played with source maps much AND the information available online regarding this specific matter is [quite insignificant](https://docs.google.com/document/d/1U1RGAehQwRypUTovF1KRlpiOFze0b-_2gc6fAH0KY0k/edit?pli=1) which *explicitly* detail what kind of paths should we use. So I had to take inferences (from td.map, scss.map) and few assumptions.

Having said that, if someone is *black-belt* in SourceMaps and experiencing issues with Web essentials generated source maps' path, please explain the requirements and we shall fix it. Note that it will be a hassle to support absolute URLs in addition to relative URLs, but nonetheless, its definitely doable.