some changes

1. I have committed lots of changes, mostly code cleanup (still some more remain to be done) + some bugfixes.
2. Objective function in LLSP have been changed from ||Cx-d|| (lapack-, BVLS-style) to 0.5*||Cx-d||^2 (BCLS, lsqlin, lots of other LLSP solvers style).These changes are required to simplify writing llsp2nlp converter. Also, some optional fields like those from BCLS will be added to LLSP soon.