Fix multiple local variables decls in FF.

Fix #679. Re-work code to be more portable.

Change-Id: I5f876cb7373970162ae13ead8932bff1e8ec525a
Fix error alert on compilation failure.

Fix error alert on compilation failure to show the error coming from
the Kawa compiler.

Change-Id: Ia80ed641a60336f37489b2c964eaabfef83d108f