Update configure.ac

* Find Vala
* Remove Python related checks
* Some minor refactoring

m4/valac.m4

@@ -0,0 +1,76 @@
+dnl vapigen.m4
+dnl
+dnl Copyright 2014 Daniel Espinosa
+dnl
+dnl This library is free software; you can redistribute it and/or
+dnl modify it under the terms of the GNU Lesser General Public
+dnl License as published by the Free Software Foundation; either
+dnl version 2.1 of the License, or (at your option) any later version.
+dnl
+dnl This library is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+dnl Lesser General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU Lesser General Public
+dnl License along with this library; if not, write to the Free Software
+dnl Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301  USA
+
+# VALAC_CHECK([VERSION], [API_VERSION])
+# --------------------------------------
+# Check valac existence and version.
+m4_define([_VALAC_CHECK_INTERNAL],
+[
+  AC_REQUIRE([PKG_PROG_PKG_CONFIG])
+  AS_IF([ test "x$2" = "x" ], [
+    AM_PROG_VALAC($1)
+    AS_IF([ test "x$VALAC" = "xno"], [
+      check_prog=no
+      AC_MSG_ERROR([valac is not installed])
+    ], [
+      check_prog=yes
+      VALAC_VERSION=`$VALAC --api-version`
+      VAPIDIR=$datadir/vala-$VALAC_VERSION/vapi
+      VAPIDIR_UNVERSIONED=$datadir/vala-$VALAC_VERSION/vapi
+    ])
+  ], [
+    AS_IF([ test "x$1" = "x"], [
+        vala_pkg="libvala-$2"
+      ], [
+        vala_pkg="libvala-$2 >= $1"
+      ])
+	  AC_MSG_CHECKING([for $vala_pkg])
+	  PKG_CHECK_EXISTS([ $vala_pkg ], [
+	          vala_pkg_found=yes
+            VAPIGEN=`$PKG_CONFIG --variable=vapigen libvala-$2`
+	          VAPIGEN_MAKEFILE=`$PKG_CONFIG --variable=datadir libvala-$2`/vala/Makefile.vapigen
+	          VAPIDIR=`$PKG_CONFIG --variable=vapidir libvala-$2`
+            GEN_INTROSPECT=`$PKG_CONFIG --variable=gen_introspect libvala-$2`
+            vala_datadir=`$PKG_CONFIG --variable=datadir libvala-$2`
+            VAPIDIR_UNVERSIONED=$vala_datadir/vala/vapi
+            VALA_GEN_INTROSPECT=`$PKG_CONFIG --variable=vala_gen_introspect libvala-$2`
+	    ], [
+	          vala_pkg_found=no
+	          AC_MSG_ERROR([no package libvala-$2 is installed])
+	    ])
+	  AC_MSG_RESULT([$vala_pkg_found])
+  ])
+	AC_SUBST([VAPIGEN])
+	AC_SUBST([VAPIGEN_VAPIDIR])
+	AC_SUBST([VAPIDIR])
+	AC_SUBST([VAPIDIR_UNVERSIONED])
+	AC_SUBST([VAPIGEN_MAKEFILE])
+	AC_SUBST([GEN_INTROSPECT])
+	AC_SUBST([VALA_GEN_INTROSPECT])
+	AC_SUBST([VALAC_VERSION])
+])
+
+dnl Check VAPIGEN
+# VALAC_CHECK([VERSION], [API_VERSION], [DEFAULT])
+# --------------------------------------
+# Check vapigen existence and version.
+AC_DEFUN([VALAC_CHECK],
+[
+  _VALAC_CHECK_INTERNAL($1,$2,$3)
+]
+)