move touch_start from core to api

[NikkiLacrima]

This is probably a matter for OC 9, and I dont know the grand plans for that release , but let me just make the suggestion ...

There are two interfaces to a collar, the touch and the command line, or technically the touch_start and the listen event, it makes sense for both to be handled in the same file, together with auth checking ( not necessarily the access editing controls ), and as it looks now that would be in oc_api.

This can allow us to efficiently handle access conditions like

• No messages from blocked avatars , except wearer will be allowed through, making BLOCKED imply NOACCESS except for wearer, of course this implies that CMD_BLOCK is actually nothing else then CMD_WEARERBLOCKED.