Metermaids and devicestate providers - new feature in svn trunk

Yesterday I committed what started as "metermaids" to svn trunk. This code started with a question on the IRC one evening:
- "Why can't I have blinking lamps for a parking lot?"
Well, now you can. Metermaids is now part of svn trunk - the ability to watch a parking lot, to have a blinking lamp as soon as someone is parked on a parkinglot in Asterisk. Metermaids is implemented using a new architecture called "devicestate providers". With those, we can add status for various non-channel related objects in Asterisk, to provide status updates in AMI (manager interface) and through SIP subscriptions. Currently, there's an implementation for parkinglots and MeetMe conferences.
So in your Asterisk, you can now add a hint pointing to park:701@parkedcalls. This means that the state of this extension depends on the state of parking space 701 in your parking lot.
Hopefully, the multiparking branch will soon be integrated too, which gives us the ability to define multiple parking lots within Asterisk. Multiple parking lots and blinking lamps for a parking lot - parking is much improved in the coming version of Asterisk!