Update Neat.completions to not trim the contents

I first noticed that the variables were being trimmed when using max-width in a media query. 

I was typing max- and then hitting tab and all I was getting back was "width: 1024px;"

I also added $ to the variables so you could determine which trigger was what.
Merge pull request #6 from lindleywhite/master

Update Neat.completions to not trim the contents