Drop duplicate database indexes

These duplicate indexes were found by the pt-duplicate-key-checker
tool in percona-toolkit.  Duplicate indexes waste space and slow down
the query planner.  Closes #835.

Signed-off-by: Anders Kaseorg <andersk@mit.edu>
Merge pull request #427 from andersk/duplicate-indexes

Drop duplicate database indexes
rebase translations, update script to maybe extract more translations from js files (fuck you xgettext you piece of shit)
Temporarily disable entity loader when importing XML file.
Merge pull request #429 from dzaikos/master

Temporarily enable entity loader when importing XML file.