Makefile: link all libraries which are required

Rather than relying on the proper symbols to be loaded by bitlbee, link
all libraries which are required by the plugin. This should help avoid
library mismatch issues.
steam: fixed potential NULL pointer dereference with user statuses

There was a rare corner cases that might allow for the dereference of a
NULL pointer with steam_user_status(). The steam_user_status() function
should gracefully attempt to grab the bee_user_t if it is NULL, rather
than relying on the caller to NULL check the bee_user_t.
steam-api: fixed information requests not populating

If a SteamApiReq had more than SteamUserInfo with the same SteamUserId,
the SteamUserInfo would be skipped. The solution is to reverse the way
in which GHashTables are used for SteamUserInfo population.
steam-util: refactored steam_util_markup_unescape_text()
Version bumped to 1.1.1