i18n: Use horizontal, alt tabs for translatable content tabs

Reviewed-By: Peter Rotich <peter@osticket.com>

orgs: Add ticket sharing feature

Reviewed-By: Peter Rotich <peter@osticket.com>

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.

Conflicts:
	WHATSNEW.md
	include/class.ticket.php
	include/class.topic.php
	include/staff/faq-view.inc.php
	include/staff/helptopics.inc.php

Fix for issue #2557 

Reviewed-By: Peter Rotich <peter@osticket.com>

Fix issues deploying with PHP 5.6

Reviewed-By: Peter Rotich <peter@osticket.com>

db: Forbid static zones like 'CDT'

Reviewed-By: Peter Rotich <peter@osticket.com>

Send header information before output. Fixes #2554

Reviewed-By: Peter Rotich <peter@osticket.com>

lock: Fix lock timing if php and db use different time zones

Reviewed-By: Peter Rotich <peter@osticket.com>

Blank page from 'register' link in notification email to guest user.

Reviewed-By: Jared Hancock <jared@osticket.com>

Fix posting-user determination in Thread::postEmail

Reviewed-By: Peter Rotich <peter@osticket.com>

reduce memory usage when storing file in DB

Reviewed-By: Jared Hancock <jared@osticket.com>

include @greezybacon suggestion on fix

Fixes #2350 in `develop`

forms: Forbid adding deleted forms to topics, form management

Reviewed-By: Peter Rotich <peter@osticket.com>

search: Improve typeahead results and performance

Reviewed-By: Peter Rotich <peter@osticket.com>

Input type= adjustment

Reviewed-By: Jared Hancock <jared@osticket.com>

Firefox form style fix

Reviewed-By: Jared Hancock <jared@osticket.com>

tickets: Fix subject display for non text fields

Reviewed-By: Peter Rotich <peter@osticket.com>

UI fix for delete button highlight - 2456

Reviewed-By: Jared Hancock <jared@osticket.com>

tasks: Assignment on task create

Reviewed-By: Jared Hancock <jared@osticket.com>

search: Add search for closed date

Reviewed-By: Peter Rotich <peter@osticket.com>

Changed logo displays on save

Reviewed-By: Jared Hancock <jared@osticket.com>