Wrong variable name in Mentions controller while marking all mentions read

Signed-off-by: emanuele <emanuele45@gmail.com>
Work around the undefined index custom_fields in ProfileOptions.template.php

Signed-off-by: emanuele <emanuele45@gmail.com>
And a little better workaround for the undefined index custom_fields

Signed-off-by: emanuele <emanuele45@gmail.com>
Merge pull request #1771 from emanuele45/fixes

Fixes