* configure.ac: Add js as language.
* lang/Makefile.am: Add js as dist language.
* lang/js/BrowserTestExtension/Makefile.am,
lang/js/DemoExtension/Makefile.am,
lang/js/Makefile.am,
lang/js/src/Makefile.am: Populate EXTRA_DIST variables.
--
There is no actual build done yet as there seems to be
no way to build it with debian stable tools. This needs
clarification.