This will enable porting things to binding/expression lookup.
I probably didn't _really_ need to make everything properties, but that was easier to do than figure out which ones would really be needed.
Testing Done:
Ran discovery on `pidgin.im`; saw `conference.pidgin.im` show up, then expanded it and the various rooms appeared, as they should. Clicked Add on a few and verified that the Add Chat dialog appeared with the correct values.
Reviewed at https://reviews.imfreedom.org/r/2210/
Title: File Transfer Signals
Slug: file-transfer-signals
## File Transfer Signals
### Signal List
*[file-recv-request](#file-recv-request)
### Signal Detail
#### file-recv-request
```c
voiduser_function(PurpleXfer*xfer,gpointerdata);
```
Emitted before the user is prompted for an incoming file-transfer. Plugins can intercept the signal to auto-accept/auto-reject the requests. To auto-accept the file transfer, use purple_xfer_request_accepted(). To auto-reject, set the status of the xfer to PURPLE_XFER_STATUS_CANCEL_LOCAL.