Workaround for gnomekeyring mercurial.demandimport incompatibility

mercurial.demandimport, which is enabled while in a mercurial extensions,
prevents the correct import of gobject._gobject and consequently doesn't
allow the loading of the gnomekeyring module, which can be used by
keyring. This just adds the proper module to demandimport ignore list.

mercurial_keyring.py

@@ -18,6 +18,13 b' except:'
 from mercurial.httprepo import httprepository
 from mercurial import mail
 
+# mercurial.demandimport incompatibility workaround,
+# would cause gnomekeyring, one of the possible
+# keyring backends, not to work.
+from mercurial.demandimport import ignore
+if "gobject._gobject" not in ignore:
+    ignore.append("gobject._gobject")
+
 import keyring
 from urlparse import urlparse
 import urllib2