Added setblockmessage and placemessageblock Actions

[bravelycowering]

setblockmessage

Works similarly to setblockid, except it queries the message at the location instead of the block id.

placemessageblock

Places a message block at the specified coordinates with the specified block ID with the message provided. If no message is provided, it places a normal block and removes the message from that location. The main difference between this action and simply using cmd mb being that it functions similarly to placeblock, where anyone running the script will allow the message block to be placed. [block] is converted to the proper message block IDs in the same way as the /mb command (white -> White_Message, air -> Air_Message, etc.) This also does the same permission checks on the contents of the message block as cmd does before attempting to place it.

[Goodlyay]

Can you remind me to review this after the holidays