Use culture-aware string comparisons

This is also more efficient; it creates fewer string instances.
Minor fixes
Use single giant regex for JSHint exclusions
Use iterators in CSS completion providers
Don't insert anything if font picker is cancelled
Merge branch 'master' of github.com:madskristensen/WebEssentials2013 into code-cleanup

Conflicts:
	EditorExtensions/Commands/Shared/RemoveDuplicateLinesCommandTarget.cs
	EditorExtensions/Commands/Shared/SortSelectedLinesCommandTarget.cs
HTML-encode extracted filenames
Refactor remove empty lines
Merge pull request #24 from SLaks/code-cleanup

More code cleanup