Random changes and tweaks + new example db with working "say" verb:

* Hacky fixed scrolling bug when showing editor pane
* Added client-side 'clear' command
* Tweaked eval and verb context mechanism a bit
* Added the ability to create new verbs on existing objects: edit #<objectid>.<newverbname>
* Added player broadcast function (send message to all other players in the same location)
* Added "say" verb and tweaked other verbs to broadcast in example db