CMosek added variable bounds

Hey @iglesias I made changes in Mosek.cpp for adding bounds on variables. Unfortunately, I have to touch many files to make the arguments consistent. Could you review the little patch for me? 

I am not sure we want to add unit-test for Mosek related class. But I am pretty sure these changes make sense. I have tested them on my own computer. BTW, I think @Jiaolong will test this part of code in his GraphCut inference thoroughly. 
I would say we either need these setters or do the unit test in a different way (e.g. testing it through classes that use different configurations of lb and ub). I do not really as an option to copy paste in the unit test the code we want to test.