Change the row bound rounding rule to tolerance based when set up the LL/SL problem

[yuxies]

In the function `setUpModel()' in MibSBilevel:

• remove the rounding on the original row bounds b^2;
• add a tolerance check before rounding values b^2 - A^2 x.

[tkralphs]

I don't think we even need rowLb and rowUb now. About all that happens is that we copy from one array to another, possibly negating the values. But then that new array is only used once after that and we could easily just have origRowSense[index1] == 'G' ? origRowLb[i] : - origRowLb[i] instead of rowLb[i]. What do you think?

[yuxies]

We can, except for the initial setup.

For newOSI, we need rowLb and rowUb to store the rearranged \llv\ row bounds and send them to loadProblem(*newMat, colLb, colUb, objCoeffs, rowLb, rowUb). After that, we can use additional condition checks, origRowLb and origRowLb when iterating over \llv\ rows. Some loops on \llv\ rows in setUpModel() can be further combined and cleaned up.

But since we have to use them once at the initial setup, we can also keep using them to make the code blocks easier(consistent?) to read.....

[tkralphs]

OK, I see.