Restore previous regex extraction method

New code seems to have caused a few other issues, and the reason
for having changed it doesn't apply anymore (fixed elsewhere
already), so might as well restore this one :)

Fixes matthiasmullie#146

Fix ASI regex extraction

Fixes matthiasmullie#143

Move line-feed normalization, to only affect code files, not file imp…

…orts

Fixes issue matthiasmullie#139

php-cs-fixer

Fix 0px minification in calc()

Fixes issue matthiasmullie#137

Add test for issue matthiasmullie#136

Shorten colors some more if their color name is shorter

As suggested on issue matthiasmullie#109

Fix '0' being replaces by first string's value

Fixes matthiasmullie#99

PHPDoc cleanup

Don't strip } when stripping empty tags preceeded by 2 }s

Fixes matthiasmullie#92