Merge pull request #1028 from matejonnet/master

Allow to pass external JAVA_OPTS.
Added test for #945
Make sure that anonymous functions (which get converted into Callables) are marked unboxed
Fixed #945 Support statement closures
StatementTransformer: annotations don't include "" anymore, so assertion messages neither

It used to be that because assertion doc annotations literals would include the surrounding
quotes, the messages would be: Assertion failed: "message", but now it is:
Assertion failed: message, so I reflected that in the assertion message for the for range
optimisation.
Marked a test as failing
Merge pull request #1031 from matejonnet/master

Fixed quotres in .bat file.
Optionaly start Ceylon in backgroud and store PID in defined file.