This addresses issue where Client side FAQ Last Updated time was showing incorrect Category Last Updated time.

Refactor PR #3410 to drop extra commits.
All credit to @jdelhome3578

Remove extra ` ` which throw off the spacing

This fixes sorting and total ticket count.

Adding possibility to use translations for some texts on homepage and main knowledgebase page.

This partially reverts a change in the ORM changing the QuerySet::all()
method to return an Iterator rather than an array. I spent a while proposing
a patch to replace usage of all() with iterations; however, I cannot propose
a valid reason to abandon the previous methodology.

This reintroduces the previous behavior: calling all() will yield an array
of results from the QuerySet's iteration system.

This is my attempt at removing similar texts from the translator work load.
It also makes an attempt at dropping some misspelled words and works toward
standardizing some phrases.

Strip tags on text input field to prevent potential XSS exploit.

Add a global option to disable avatars on thread correspondence . Agent's
and user's profiles will still show an avatars.

Add preference to agent's profile to enable relative time use.

This feature allows (by option) an organization to allow its members to see
tickets from other members. It can be used beside or instead of the
automated collaboration feature. Now, collaborators retain access to tickets
on which they participate; however, sharing can be used to enable access to
other tickets owned by their organization.

If the subject field is something crazy, such as an HTML field, ensure that
the layout of the ticket queue is preserved and properly truncated.
Furthermore, ensure that the HTML is properly rendered on the client and
staff ticket view pages.

This patch makes the open and closed ticket counts on the client portal
relative to the help topic search. It also hides the counts when doing text
searches so that an extra count query isn't necessary.

So, fields with only the 'required' flag set for users are shown for the
registration page.

Fixes #2364

Initially, include support only for Gravatar