Consistently Case CSS in Class/File Names

[AlexCuse]

We currently have:

Type (File if different)
CSSPathRewriter (CssPathRewriter)
CSSBundle (CssBundle)
ICSSMinifier
CssAssetsFileHasher
ICssAssetsFileHasher
CssBundleExtensions (CSSBundleExtensions)
CssBundleTests
CssMinifierTests
CssPathRewriterTests

Making things even more fun the namespace is Css.

It would be nice to make these consistent. Either way represents a potentially breaking change, so may as well do this in 0.9 when we're breaking the coffeescript/less processing behavior also.

I tend to favor "Css"

[AlexCuse]

went with "CSS" to keep bundle name consistent (and because it is an abbreviation after all)