Merging Lubo's closure work into default branch. Release 0.5 will have (partial) support for effective static compilation

Adding javadoc to various obfuscation levels. Disabling MEDIUM for the upcoming merge to default, as it is not finished yet.

One can specify --obfuscationlevel when invoking the bck2brwsr compiler from command line. Forking external Java when calling into the compiler to prevent "out of perm gem" errors.

For debugging purposes it is much better to give class constructor functions fully qualified names. Obfuscation will optimize them away later anyway.

Support for callbacks from knockout to Java

Need to merge in default branch: It contains automatic conversion of boxed types to primitive values which is needed by Knockout to display elements of arrays properly.

Modifying the calculator example to work with array of objects

Allow boolean properties

Report location where non-primitive type is used

Using cummulative factory with the hope to prevent enormous increase in overloaded 'generate' methods