Improved java errorhandeling and fixed JS calls

After each JVM call, a check for exceptions is run and if found printed
to System.err and _MESSAGE.
JS - Java calls were also fixed. The jmethodID of the first object was
used for all handlers which broke invocation of these handlers
Added support for including html files

Using <!-- SUBCOMPONENT htmlfile.html --> now makes sure that this file
will be extracted to the working directory for display.
Added disabled style for submit button