Additional refactoring of block packing to be used with message
parameter packing.

Also added support for non-initialized fields and properties to
language.
Corrected send message function.

- We now should correctly be constructing and sending messages with only
  a payload.
- More complex messages to come soon, but first I plan to implement the
  message loop for messages with just a payload.
- Once complete, we'll be able to implement the Timer component