steam-friend: properly parse and store SteamIDs/CommunityIDs

This significantly cleans up and unifies the SteamID/CommunityID parser
and storage methods. Previously, IDs were incorrectly parsed and there
was a lot of information missing, such as the ID type and universe. This
will enable the plugin to fix current issues and implement features down
road where this information is essential. In addition, this prevents the
plugin from having to constantly reparse IDs all over the place as IDs
are now centralized in one object.
Gracefully handle NULL pointers in all freeing functions

Not everyone has the glib debugging macros enabled to return on NULL
pointers. And occasionally, NULL pointers will be passed to a freeing
function, which should just gracefully handle it.
steam-api: only handle poll messages from individuals

Several of the Steam Web API operations only work with certain types of
SteamIDs. Since this plugin only handles operations for individual Steam
friends, it should be ensured no other SteamIDs make their way into the
plugin.

This fixes the plugin getting an empty summary list when starting the
desktop Steam client.
steam-friend: fixed channel modes not being overridden

When steam_friend_chans_umode() is used to set the channel mode(s) of a
SteamFriend, the mode(s) do not override existing modes. This prevents
modes of a lower standing from being set correctly.

This patch will simply unset all other mode flags that are a higher
standing than that of the mode(s) being set.
steam: fixed segfault when setting `show_playing`

This segfault occurs from the account or bee_user being from a different
account or invalid. This issue seems to only be noticeable while the
steam account and a skype account are both online.

In order to resolve this issue, conditional checks have been implemented
to ensure the account and bee_user are valid.
Version bumped to 1.0.1
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.