Extrema_ExtCs.cxx: number of subdivision is incresed for curve;
Modifications to fix regressions of some tests
IntTools_BeanFaceIntersector.cxx: restriction of curve, which is used in Extrema_ExtCS
ProjLib_CompProjectedCurve.cxx: tolerance is reduced for Extrema_ExtCS
BRepOffset_Tool.cxx: checking common vertex if it is Null
tests/bugs/modalg_7/bug27087 : test case added.
tests/bugs/modalg_5/bug25232_8 : test is modified according to new behavior of algorithms
