JSMin should not be the default JS Minifier

[omarqureshi]

I've noticed a few bugs in upgrading from Jammit 0.6.5 to 0.6.6 - mainly where people have forgotten to add semi-colons in Javascript files.

Additionally the JSMin maintainer has given up on maintaining it and recommends not using it (https://github.com/rgrove/jsmin), why was the default changed in #227 ?

Can we revert this back to yui as the default?