Checkin overhual for extensions, including item, patron and checkin underpinnings.

Checkin overhual for extensions, including item, patron and checkin underpinnings.

Extensions fields added to AUTOLOADable content.

Also fix checkin logic to check for NO_CHANGE and SUCCESS at necessary moments.

Update new code to match berick's #16544.

Add AUTOLOAD to Item and provide a slot to store the raw EG hold object.
Store the hold data down on the item (not the Checkin transaction level).

Allow SIP Patron lookup by usr ID (not barcode).
This is important because we need supplemental data when we find holds info at checkin.
The change is backwards compatible (w/ just 1 arg  it will still be treated as a barcode).

Propagate $inst_id down into checkout core, needed for hold routing logic.

Remove old accessor methods, also make some of the settings checks more flexible w/ regex.

git-svn-id: svn://svn.open-ils.org/ILS/trunk@16599 dcc99617-32d9-48b4-a31d-7c20da2025e4