Preserver mediaqueries

This searches all style tags for Media Queries, and replaces the content with just those. Fixes #45

Also set the default to strip mediaqueries from inline tags, because that doesn't work as expected. (at least, not after #52)

Not sure if this is the most performant/optimal way, so open for ideas ;)
Refactor specificity

Don't use a value, but compare the 3 values in a seperate class. And
don't add the order to the specificity, only use it when the specificity
is equal.
Merge remote-tracking branch 'origin/patch-1'
Merge remote-tracking branch 'origin/patch-3'
Merge remote-tracking branch 'origin/specificity'

Conflicts:
	CssToInlineStyles.php
Merge branch 'master' of https://github.com/barryvdh/CssToInlineStyles