I nuked common/tobuild (and restored it) very sorry!

[Quentin Spencer]

Hans de Goede wrote:

> Perhaps it is a good idea to let the make build target in
> makefile.common fail if one of the steps fails.

I agree. For some reason lately, when I run make build, sometimes it
does nothing--tobuild is not updated--and it just returns to the prompt
without any error messages. Today I had to in one case run make build
about 3-4 times before it worked, with no idea why it didn't work the
first time.