BRepAlgoAPI_Cut improvements

The following 2 commits should directly calculate the number of periods to subtract or add thus eliminating the need for any iterations. It was brought up on the mailing list that these parts can iterate for a long time. We need any performance gains we can get for BOPs. Note: I used the functions Ceiling() and RealToInt() from Standard_Real.hxx instead of the math.h functions directly. Also, the loops could be eliminated entirely but @dbarbier agreed that the less we can change here the better.