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: Command Signals
Slug: command-signals
## Command Signals
### Signal List
*[cmd-added](#cmd-added)
*[cmd-removed](#cmd-removed)
### Signal Details
#### cmd-added
```c
voiduser_function(constgchar*command,
PurpleCmdPrioritypriority,
PurpleCmdFlagflag,
gpointeruser_data);
```
Emitted when a new command is added.
**Parameters:**
**command**
: The new command.
**priority**
: The priority of the new command.
**flag**
: The command flags.
**user_data**
: User data set when the signal handler was connected.