Compiler for ChannelMathController

shhhhh

Now supporting if/else and while

There are new options in the controller - waiting means that there can be multiple concurrent program 'threads'.

• Blocked: The next attempt to start will not be permitted until the previous has finished
• Replace: The next attempt to start will immediately replace the previous, terminating it
• MultiAttached: Multiple contexts can be active at once; all will be updated by channel changes
• MultiDetatched: Multiple contexts can be active; once they are, their channel state is frozen.

Execution can branch <3