- fixed bug concerning unsafe removing of redundant rows from the LP
   - support to start project and shift method down in the tree instead of only at the root now
   - added possiblity to set a timelimit for the exact LP solver (but disabled because of bug in QSopt_ex
   - temporary disabled to set an objective limit for the inexact LP solver even in inexact mode in
     order to get a fair comparison to exact mode where its disabled because of bug in QSopt_ex