returning projectPath in server callback

Merge pull request sintaxi#502 from sintaxi/release-v0.20.0

Release v0.20.0

npm v3 compat

node v4.x compat

upgrades to sass, less, jade

node v0.12.0. sass v2.0.1. w00t

reverts node-sass to v0.9.0

add minification, preprocessor bumps. sass, auto-prefixer, coffee-scr…

…ipt, less

auto-prefixer support

Bumps version to v0.13.1