[Feature Request]add equipment's "in use" status

[wpcfan]

In my company, we have strict rules on the equipment management:

1. When someone need to get some devices, he needs to go to a "device manager"
2. and sign on the device checkin table, where there are some fields need to be filled out: the name, device no, device serial, request date, return date, and signiture.
3. Once a device is in use, others cannot get it unless the device is returned

[sukima]

In my company there is no check out. Equipment floats around. That is why I focused on a foursquare like check in system. I realize that future versions of this plug in should allow a check out policy as well.