[gtksourceview/wip/exterminate-intltool] i18n: add rules to generate the sub *.pot files

[Sébastien Wilmet <swilmet src gnome org>]

commit 612aeff2db3839bb2ea5d6291dbb557416dc2057
Author: Sébastien Wilmet <swilmet gnome org>
Date:   Wed Aug 12 18:31:45 2015 +0200

    i18n: add rules to generate the sub *.pot files
    
    The 'make distcheck' error was:
    make[3]: Entering directory '/home/seb/gnome/gtksourceview/po'
    make gtksourceview-3.0.pot-update
    make[4]: Entering directory '/home/seb/gnome/gtksourceview/po'
    make[4]: *** No rule to make target '../data/glade/glade.pot', needed by 'gtksourceview-3.0.pot-update'.  
Stop.

 po/Rules-itstool |    8 ++++++++
 1 files changed, 8 insertions(+), 0 deletions(-)
---
diff --git a/po/Rules-itstool b/po/Rules-itstool
new file mode 100644
index 0000000..a24a385
--- /dev/null
+++ b/po/Rules-itstool
@@ -0,0 +1,8 @@
+../data/styles/styles.pot:
+       (cd ../data/styles/ && $(MAKE) $(AM_MAKEFLAGS) styles.pot) || exit 1;
+
+../data/glade/glade.pot:
+       (cd ../data/glade/ && $(MAKE) $(AM_MAKEFLAGS) glade.pot) || exit 1;
+
+../data/language-specs/language-specs.pot:
+       (cd ../data/language-specs/ && $(MAKE) $(AM_MAKEFLAGS) language-specs.pot) || exit 1;