#1 Replace DSA with malloc

[Patrick Miller]

Should use malloc for serial model. Pthreads can also
use the same malloc (at least in the _r libraries).
The DSA is a holdover when we needed to allocate special
shared memory pools (History note: We needed this to
make shared memory work on a 8-way parallel cluster of VAX
called ``circus.'' We also had a 2-way VAX called ``dumbo.''
Shared memory pages were mapped so that page maps for
each processor were overlaid via special calls).

Anyhow, the DSA technology is old and we should not
run with it if we don't have to. A particular annoyance
is requiring the memory requirements to be set before
run starts. The original 10meg DSA size is ludicrous.