Merge baseudev into storage.udev.

This is the first pass at setting things up to split storage out into
a separate package.

It replaces the guts of iutil.execWithRedirect and iutil.execWithCapture
with a single backend function, _run_program. The main thing I can think
of that might be cause for complaint is that _run_program does not log
each output line as the external program outputs it, so you get the whole
output buffer at once. Storage gets its own copy of _run_program and
all of the calls in storage use the copy from storage.util.

The reason I moved all of the iutil arch functions into storage is that
they are mostly used in storage and I didn't want there to be two copies
of the whole set.

The rest is removing of unused things and moving of things only used by
storage into storage.

These have all been merged with the new text interface.

I've had to leave pieces of text.py around, though, because it's used by
rescue mode and we're not changing it quite yet.

The rules for hostname are more strict. Also, it was not easy to use
this function because of its return values.

Related: rhbz#865869

Fix the TypeError problem with iutil.execWithCapture() when fatal
and process returns a non-zero exit code.

Good riddance.