pidgin/pidgin

Add the cpu, cpu_family, and endianness of the host machine to the about dialog

Also added the Adwaita version as that'll be handy too.

Testing Done:
Opend the about box and verified there weren't any warnings and that all of the data looked accurate.

Reviewed at https://reviews.imfreedom.org/r/2910/
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
void user_function(PurpleXfer *xfer, gpointer data);
```
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.
**Parameters:**
**xfer**
: The file transfer.
**data**
: User data.