configure: bumped glib version to 2.32.0

The required glib version has been bumped from 2.14.0 to 2.32.0 for the
plugin. While this goes against the required glib version of the upsteam
bitlbee project, it prevents the plugin from having to supply local
compatibility symbols. In addition, the plugin will make use of newer
glib symbols when features are later implemented in the plugin.

This may raise issues from some individuals who are running ancient glib
versions, however, glib-2.32.0 was released just over two years ago.
steam: reorganized information output

This cleans up and condenses the output of the info command.
Refactored enumerator translations

This cleans ups, and unifies similar code blocks.
steam: implemented additional state information

Additional information is available for Steam friends which holds flags
pertaining to the friend state. This includes determining if a friend is
using a web or mobile client as well as big picture mode.
steam: implemented last online information

The last online time is sent via the user summary request, and has been
for quite sometime. The plugin should make use of this timestamp, and
show the user when a friend was last online.