Custom username support to allow for room invites

[fidian]

Would it be possible to expand this plugin to also address the difficulties that people have when trying to get HipChat connected? Another hurdle is accepting room invites. The Pidgin developers think that a plugin would be the ideal way to handle this particular problem.

Another idea would be to support the emoticons that HipChat provides to bring this more in line with the official HipChat client.

HipChat's documentation: https://confluence.atlassian.com/display/HIPCHATKB/Connecting+to+HipChat+using+Pidgin

Pidgin bug report: https://developer.pidgin.im/ticket/6388