Address or suppress warnings.

Add `-deprecation` to `scalacOptions`, and `-Xlint:unchecked` to `javacOptions`, so we see details of warnings.

For *Classpaths.publishConfig* is deprecated*, set `overwrite = true`.

For *unchecked cast*, add `@SuppressWarnings("unchecked")`.

For *Possible heap pollution from parameterized vararg type T*, add `@SafeVarargs`.
Merge branch 'pr-142' into merge-142

Conflicts:
	project/plugins.sbt
Fix travis build.
Merge branch 'master' into merge-142-with-travis

Conflicts:
	.travis.yml
Merge branch 'merge-142-with-travis' into travis-java-6-7