removes unnecessary gulp stuff, adds more config options and cleans readme

A bunch of things going on here:
1.  Compass has built in compression and auto-prefixing so I removed those gulp modules, there really isn't a reason for them and gulp-if is gone too.
2.  I added a bunch more config options things like images are important for sprites.
3. Created a config file to just make it a little cleaner
4. Cleaned up the readme file to remove references to Stylus and talked about some of the new options
5.  Bumped the version to 0.2.0 because I changed the signature of the ```compass``` function

I tested this locally and it's working fine, but I'm sure if could use a good once over by some other people.