introduced option allow_multiple_sessions
wip detecting new session of an existing occupant
wip change default value of allow_multiple_sessions to false, check if it is set
wip add dictionary of occupants sessions in a room
wip fix indentation
minor refactoring - introduce presence status codes
use existing function for status codes
wip change routing to given nick
fix; compare ljids instead of jids
fix commas
fix - send presence <<unavailable>> to all only in last session
fixes for version without multiple sessions allowed
fix update sessions dict on kicking out
Applied some changes suggested by @fenek
Changed ugly case expressions
Function find_jids_by_nick/2 always returns a list
Changed values of #state.sessions dict from lists of LJIDs to lists of JIDs
Fix not changing nick in sessions dict on nick changes
Merge pull request #246 from pianiel/muc_multi_session

Allow multiple resources for the same JID in a MUC room