[Swan-dev] Some makefile variable tweaks

[Andrew Cagney]

Hi,

I've been trying to get dependencies working better (there's a patch
kicking round for pluto).  Unfortunately, it went a little pear shaped
as each directory I looked at was annoyingly different.  I'd like to
impose a little of my view of sanity on the following:

- while OBJDIR is assumed, make files are hedging their bets
-> I'll remove code assuming otherwise

- $(srcdir) and $(SRCDIR) are kind of redundant, while they might
designate the same directory they are not even internally consistent.
For instance, "./", "$PWD" and "$PWD/" are all found
-> I'll remove the existing $(srcdir) definition, and have SRCDIR be
consistent - absolute and with a trailing / - so existing code works

- add a full set of directory variables THAT DO NOT ADD A TRAILING /
so I can use those.  For names I stole from autoconf: relative:
srcdir, builddir, top_srcdir, top_builddir; absolute: abs_srcdir,
abs_top_srcdir, abs_builddir abs_top_builddir.

Andrew