Removed redundant functionality

This feature is built in to VS2013 RTM
Fixed issue with CSS classifiers
Fixed rules.length null error

Some Chrome Extension add style sheets to the page and the rules can't
be access or return null.
Merge pull request #132 from davidtme/master

Fixed rules.length null error
Updated packages. Version 1.0
Using HTML minifer instead of XHTML
Fix Add _references.js command

Command now correctly disappears on other folders, and works on the
project level too.
Add Go to Definition for Javascript <reference>s
Merge pull request #140 from SLaks/js-ref-def

Add Go to Definition for Javascript <reference> tags
Allow app-relative paths in reference go-to-def
Hide _references.js command for non-web projects
Merge pull request #141 from SLaks/js-ref-def

Hide Add _references.js command for non-web projects
Fix relative path completions in CSS URLs

ToAbsoluteFilePath() was being called incorrectly; I fixed the call and
clarified the parameter names
Comments & general cleanup for ProjectHelpers

Mostly tested.
Merge pull request #142 from SLaks/path-fixes

Path fixes
Collapse minified JS & CSS files

Unfortunately, this doesn't work for LESS files; not sure why
Don't add url() for dropped LESS imports

See workaround for #134

Also refactored code
Merge pull request #147 from SLaks/more-nesting

Nest CSS & JS files
Fixed #127
Fixed #139