Added ability to move version.sbt to a custom location. Default to version.sbt
Fix 0.7.1 release notes
Set version to 0.8-SNAPSHOT
Overridable mechanism for automatic cross releases.

Fixes #29.
Merge remote-tracking branch 'origin/pr/44'

Conflicts:
	src/main/scala/ReleasePlugin.scala
Update README.md
Don't write any line separator to version.sbt.

Fixes #21.