Changes of interest
o unit-tests: use private TMPDIR to avoid errors from other users
o avoid strdup in mkTempFile
o always use vfork
o job.c: do not create empty shell files in jobs mode
reduce unnecessary calls to waitpid
o cond.c: fix debug output for comparison operators in conditionals
Lots of new unit-tests increase code coverage.
Lots of refactoring, cleanup and simlpification to reduce
code size.
Fixes for Bug 223564 and 245807
Updates to dirdeps.mk and meta2deps.py
