[PERF] Ember Twiddle browserify / babel performance

[Gaurav0]

See ember-cli/ember-twiddle#359

[ProLoser]

I'm getting build times of 1-2 minutes initially and rebuilts of 10-20 seconds. I'm using babelify inside of one of the browserify'd packages but this is only adding about 10 seconds.

I also wrote a standalone test that's about 40 lines of code in total (app + addon + browserified node package) and browserify turns a 4 second load time into 8 seconds.

[stefanpenner]

some build stability improvements here

Going to be working on improving warm boot times next.

[Gaurav0]

Removed browserify for now.