Lots of edits to remove all dynamic linking and symbol munging.

Load up all implementations of colletives, then just assign pointer
according to env var or a default.  Looking for nicer, more generic,
way to do this, but the logic appears right, so fine-tune later.

Split barrier and barrier_all to make it easier to distinguish code
(h/w may provide best barrier_all, while there'd be some s/w between
barrier and h/w).

Deepak and co's better reductions to be folded in later.

Hard-code ELF parsing routine in globalvar.c for now, this will eventually
be detected and config.h'ed by autotools.

Migrate Makefile.in to create static .a archive instead of shared object.
autotools can help us generate both later.