Compile from an atomic function.

So that an error in object->compile() can roll back the compilation.
Simplify private per-program TLS interface.
Implement message passthrough for atomic rollback.
Only inheritables can have undefined functions.
Use unique TLS indices for atomic rollback messages.
Skip pre-compile space check.

Atomic compilation means that running out of space in objectd is
recoverable.
Go back to all-caps macro definitions.

The exception is for object types only.
query_atomic_messages() => get_atomic_messages()
Allow forwarding of errormessages.
Switch upgrade manager to the atomic message system.