Add test suite for Java regex emulation.

This fixes several issues in the regex implementation:

 - Calling match accessors before find should throw
   IllegalStateException.
 - `Matcher.hitEnd` should return true if last match failed.
 - `Matcher.appendReplacement` should return the matcher.
 - Implement support for `Matcher.region`.

Fixes #108
Merge pull request #112 from jonas/java-regex-test-suite

Add test suite for Java regex emulation.
Fix #117: Implement java.lang.Character.digit
Fix #109: Handle LabelDef for while (false) {}
Fix #104: Correct hash for boxed Byte, Short and Int
Fix #116: Correct comparison for boxed Float and Double
Fix #113: Prepend a Char to String
Implement java.lang.Character.isWhitespace
Merge pull request #120 from gzm0/bugfixes

Various bugfixes
Allow to publish releases to Bintray.