[FIX] Packaging: exclude *.hg* in MANIFEST.in

This fixes the lintian warning package-contains-vcs-control-file
for Debian packaging.

MANIFEST.in

@@ -23,4 +23,5 @@ recursive-include openerp *.woff
 recursive-include openerp *.xsl
 recursive-include openerp *.xml
 recursive-include openerp *.yml
-recursive-exclude * *.py[co]
+recursive-exclude * *.py[co]
+recursive-exclude * *.hg*