Mod/Group Flags added, annc added

Added Digest.groupflagsupdate (sets group.flags)
     Digest.ok sets the group.flags on connect.

group.mods is now a dict with the mod name as the key and bitflag as the value (use bin(group.flags) to get the flag representation of it)

Digest.getannc now sets a dict with the values from getannc.