This sychronizes multiple processes so fiddle files can be effectively
complied in parallel.

buffer tells fiddle to create a buffer of a number of bytes.

skip_to tells fiddle to skip to some new offset. It's essentially an
unnamed buffer

This is for expressions which must be calculatable at compile time.

This helps to catch bugs in the compiler, specifically ones related to
mixing up bits and bytes.

This is primarily done by making more things json and by instrumenting
which stage in compilation to dump and others. This means I can make
bash scripts for end to end testing.

Big change. Implements qualification, which separates the qualification
concerns from the ConsistencyCheck phase.

I'm getting close to implementing a backend.