This removes some redundancy in creating messages, but also allows
a lazy form or parsing without explicitly checking the type.
A helper fromwire_peektype() is added to look up the type and handle
the too-short-for-type problem.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This is a bit more awkward for large structures, but avoids
indirection for the simpler ones (I copied the structures for the test
code, however). We also remove explicit padding.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
