House Coupon docs now in plugins2.0

Fixed the link fannie/modules/plugins to .../plugins2.0
BUGFIX: item/ajax.php not re-include FannieAPI

Pages such as itemMaint_WEFC_Toronto.php that include this and have already included FannieAPI will fail on trying to re-declare the class.
Merge branch 'master' into fannieDevelop
Advanced Search: movement filter, likecode option
BUGFIX to previous so that movement "n/a" option works