Port to GtkSource* API

There are still bugs but this gets it started

configure.ac

@@ -213,13 +213,6 @@ if test "x$enable_deprecations" = "xyes"; then
    AC_SUBST(DISABLE_DEPRECATED_CFLAGS)
 fi
 
-AC_ARG_ENABLE([tests],
-	AS_HELP_STRING([--enable-tests], [Enable the tests]),
-	[enable_tests=$enableval],
-	[enable_tests=yes])
-
-AM_CONDITIONAL(ENABLE_TESTS, test x$enable_tests = xyes)
-
 PLUGIN_LIBTOOL_FLAGS="-module -avoid-version"
 
 AC_SUBST(PLUGIN_LIBTOOL_FLAGS)
@@ -259,7 +252,6 @@ plugins/time/Makefile
 plugins/time/org.x.editor.plugins.time.gschema.xml
 plugins/trailsave/Makefile
 po/Makefile.in
-tests/Makefile
 ])
 
 AC_OUTPUT
@@ -273,5 +265,4 @@ Configuration:
 	Spell Plugin enabled:	$enable_enchant
 	Gvfs metadata enabled:	$enable_gvfs_metadata
 	GObject Introspection:	${have_introspection}
-	Tests enabled:			$enable_tests
 "