Added _cmd to core to allow programmatic command firing.
Tidied up Server.do.
Removed debug output from core.
Finished writing scheduler module.
Removed debug output from scheduler.
Updated todo list.
Updated changelog.
Removed scheduling code from Server.
Removed rawtimed command as this can now be done with scheduler module.
Removed test_firetimed module from iBot.
Added ability to fire  events from a different sender.
Updated module remind to use new scheduler module.
Added _fire function to scheduler.