upgrade less from 1.3.3 to 1.4.1
fix content of less-1.4.1.js
Re-factored build.scala to build.sbt thereby leveraging the new 0.13 syntax. This has the following-on effect of being able to dispense with Play's own Project object for use in sbt build files - i.e. Play now uses sbt in a idiomatic way.

Also, changes to the console that fix up jline upsetting some terminals and the play logo no longer having an exclamation mark (not part of the official logo anymore).
Merge pull request #1214 from huntc/build-sbt

Move from Build.scala to build.sbt
Merge pull request #1328 from BertrandDechoux/less-1.4.1

Upgrade less to >= 1.4.0 (will solve css optimisation)