Fix comma in composer.json
Boolean $overwrite property to switch whether existing rules are overwritten. Default true (current behaviour)
Renamed property $overwrite to $overwriteDuplicateStyles	
Replaced tabs by 4 spaces.
Merge branch 'master' of git://github.com/vanderlee/Emogrifier into vanderlee-master
Merge pull request #3 from nburka/master

Push up a couple additions from Martijn to the compser file and overwriting existing CSS classes