smdev

Specify dependencies correctly to allow parallel builds with -j.
Previously the makefiles relied upon sequential execution in order to
ensure prerequisites were built first. The new dependencies are done
on a per package level and a per directory level. For example parts of
the parted package depend on parts of the e2fsprogs package.  Instead of
listing the exact dependencies and recipes in the parted makefile, list
e2fsprog as a prerequisite for parted in the bin/stali.mk. While this
isn't as exact, and means that you can't build parted directly from its
directory, it sucks much less to implement and puts dependencies in a
more central location and makes them easier to read and add to.

Using guard files to protect against redundant recipe execution.
In some instances more than one target is built by a single execution of
a recipe. For example, the awk package uses yacc to create both ytab.h
and ytab.c from awkgram.y. However when doing a parallel build the recipe
would be executed twice in parallel, once to create ytab.h and once to
create ytab.c. In order to avoid this an intermediate rule is used. The
rule could be PHONY, but then it would run every time instead of only
when the grammar is updated. Instead the intermediate rule, called _ytab,
touches a file called _ytab so we have a modification time to compare
against. I used the convention of guard files begining with an underscore.