Force output_compression Off for downloads

Looks like a long standing, yet-to-be-fixed PHP bug, where
zlib.output_compression can result in the output buffer not completely being
flushed. This is especially critical for downloads where the tail of the
file might be lost.

https://bugs.php.net/bug.php?id=19436
Abort cron duties if upgrade is pending
Add site pages support
 - Supported pages: landing, offline, thank-you and other
Add ability set default (required) pages
Add ability to set thank you page specific to a help topic.
Migrate Email Templates to a row-based data model
Use DB based pages for landing, offline and thank-you pages.
DB patch for federated email templates and site pages
Merge remote-tracking branch 'jared/feature/pages' into feature/pages

Conflicts:
	include/staff/tpl.inc.php
	main.inc.php
	setup/inc/sql/osTicket-mysql.sql.md5