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: Core Signals
Slug: core-signals
## Core Signals
### Signal List
* [core-uri-handler](#uri-handler)
### Signal Details
#### uri-handler
```c
gboolean user_function(const gchar *proto,
const gchar *cmd,
GHashTable *params,
gpointer user_data);
```
Emitted when handling a registered URI.
**Parameters:**
**proto**
: The protocol of the URI.
**cmd**
: The 'command' of the URI.
**params**
: Any key/value parameters from the URI.
**user_data**
: User data set when the signal handler was connected.