Move memstat tracking code memstats.c

Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Make the Makefile less sad

This isn't perfect, but much better than before:

- separated out each program cfiles

- make objects variable via substition

- use implicit rule (.c.o) to build objects

- put headers into their own variable

- depend the whole thing on the headers define.
  - this is inefficient but i will provide a better way soon
  - in the meantime, changing a header doesn't require a manual
    'make clean'. This is far more 'modern' behavior.

Signed-off-by: Mark Fasheh <mfasheh@suse.de>