Escape help text for Remote field in Rule panel

As documented in django, help text does not get automatically
escaped when rendered in HTML. We have to escape the text manually.

Change-Id: I3be7b23cd16537e233cefd4d2f780c0f6c07f985
Closes-Bug: #1392510
Imported Translations from Transifex

For more information about this automatic import see:
https://wiki.openstack.org/wiki/Translations/Infrastructure

Change-Id: I5fd02915e07893515a840d06d01d25ad6f4eb222
Merge "Escape help text for Remote field in Rule panel"
Merge "Imported Translations from Transifex"
Merge branch 'master' of https://github.com/openstack/horizon