Upgrade to the latest SBT milestone - 0.13.0-M4
Removed Sonatype snapshots as we are using non snapshot artifacts throughout.
Updated samples with 0.13.0-M4
Merge pull request #1407 from huntc/sbt-013M4

sbt 0.13.0-m4
#1305 A little note to ask the user to update their Play project.
Fix a typo from "becemoe" to "become"
Merge pull request #1413 from wsargent/patch-4

Fix a typo from "becemoe" to "become"
Removed references of Play 2, Play 2.1, Play 2.0, Play20
Merge pull request #1411 from huntc/play-21-renaming

Rename Play files to current release