Give ability to define constants that may be used throught the configuration
minor: add --default-user option to "load oar" help long description.  Do other small tidies of "load oar" console command help.
Implements osForceSit(string avatar) & overload osForceSit(string avatar, string target)

Allows a script IN the target prim to force an avatar to sit on it using normal methods as if called by the client.

Overload method of osForceSit() to allow a script NOT in the target prim to force an avatar to sit on the target prim using normal methods as if called by the client.

This patch is based on previous work from
http://opensimulator.org/mantis/view.php?id=4492
and also includes the suggestions from justincc including change of threat level
Thank you Christos Lightling.
minor: spacing cleanup from previous commit 79a4d1ea
Change name of just added OSSL osForceSit() to osForceOtherSit()

This is somewhat more in keeping with something like osForceAttachToOtherAvatarFromInventory()
and potentially allows a separate osForceSit() command with High threat rather than VeryHigh that only sits the owner and can be enabled without enabling sit of other avatars.
Fix some errors in PgSQL XAssets by changing some data types. Also make sql query syntax more in line with the PgSQL AssetData implementation.
Make column names lower-case, change hash column type to bytea and remove old commented lines of code
Get V2 Groups working under PgSQL. Needed to re-create tables to satisy the generic handler type matching. There should be no existing data because it couldn't complete the first migration as-is.