Update class.mailparse.php

Best version of https://github.com/osTicket/osTicket-1.8/pull/348

static keyword added to enable strict test mode.
Update run-tests.php

Allow tester to run single test by specifying it on command line: php run-tests.php TestMyThing etc.

Still works for normal tests.
Create test.header_functions.php

Creates a regression test for the parsePriority function, as suggested by GreezyBacon https://github.com/osTicket/osTicket-1.8/pull/348#issuecomment-31326865
Initial concept for user import/export

Implement CLI user import/export in a well formatted CSV file. Name and
email address are the only supported fields at the moment.
Add ability to skip headers on import
Output headers on export
First steps for client login
Profile update for clients
Implement client timezone preference
Add settings page for access control

Add client registration methods and login required checkbox
SQUASHME: Fix missed validation move
Implement password reset for clients
Force login for clients if required
Cancel reset tokens on successful, interactive login
Add database patch for most things 1.8.2
oops: Fix client login
Add account registration feature
Move profile.php to account.php

For client account / profile updates
orm: Crash if accessing non-existent magic property
Add upgrade patch for 1.8.2 database changes
content: Add management for system templates