package: require modern gjs

gjs 1.36 is stable now, we don't need the conditional code anymore
(also because it was broken with the new style apps)
package: add minimal option parsing to the application launcher

Recognize --help and --version.
package: add better support for running uninstalled/from jhbuild

If running the launcher uninstalled, bypass dbus activation and
launch the application in process, as the service file will not
be visible to the dbus daemon.
Also, let package.js compute the application flags, and add
IS_SERVICE/IS_LAUNCHER as needed.
package: stop littering the global object with GI namespaces

Remove the magic namespace installation from require(), which now
only checks for typelib availability and version.
With that, we can also remove the hacks to have the JS modules
in require().
params: remove versioning

No longer needed, now that params is not imported through require()
gtk-js-app: update for package.js changes

Use the application flags computed from package, to get the right
value for IS_SERVICE, and pass all the parameters to the launcher
(which is now the full application in the uninstalled case)
Also, no need for the activate() hack in the uninstalled case, package
takes care of it now.
Generate the GSettings schema with configure substitutions

Turns out that insisting a bit we can get intltool to accept
gschema.xml.in with configure substitutions, and remove a
few places where the package name is hard-coded.
configure: fix the package name to dbus path conversion

Fixes the search provider file and the GSettings schema.
Update the anjuta project

Add a few useful plugins.
configure: don't make gzip tarballs

We only want xz these days.