bringing back in line with master.
Added automated test script for various constraints.
significant speedups from these small changes
one last cast to msspoly at the end of decomp
istrig edited to handle empty argument.
recomp modified to handle empty variable list
diff modified to return msspoly even when all zeros
beta support for facial reduction (do not use), and approx. by SD
updated dualize/primalize and approximation by SDD.  variables are cached now.
removing old file.
added num. error output
just rejustified a line
removed old sos prog interface
removed unnecessary comment.