This allows SSO backends to ingore authenticate method

No need to execute signal connect for each request!

SSO was originally used for a SSO plugin. The backend has since been
refactored to support other authentication backends.

Reafactor logOut to use the piggyback on auth backend

The concept of extid is being retired to pave-way for customizatable ticket
numbers.

 - This is necessary so we'll have a name on record - even on user deletion.

Pass the user id (uid) to ticket create instead of unpacked data.

Make sure new message notice goes to the user who posted the message not
neccessarily the ticket owner.

Using email headers try to determine the user.

With the introduction of collaborators, this is necessary so we can determine who is replying without relying on the
FROM address - which can be easily spoofed.

Long term 'asVar' will be replaced with __toString function

Add routine to get ticket's recipients (owner + active collaborators)

The main intension is to have a predictable length and position of
the ids - obfuscation is a welcomed side effect.

Connect to logout signal and clear upgrader session on staff logout.

Conflicts:

	include/upgrader/streams/core.sig

Drop join to the user table
Use internal ticket id instead of ticket number

Add EndUser lookup by email to TicketUser - returns a decorated user

Make Clientession extends EndUser

Allow variable replacer to call __call functions

TicketUser class - Abstract class with auth token implementation
TicketOwner class - extends TicketUser

Add user ticket stats to EndUser class

Checks the session for authkey and asks the backend that generated it to
validate it and return authenticated user.

Add ability for backends to set authorization key (authkey) specific to the backend.
The authkey is tagged with the "id" of the backend that generated it.