One bugfix and two security fixes

Hi Ben,

Peter and me found two problems in softsusy.cpp:

1. addSbotCorrection() was called with the running bottom mass as last parameter.  We think the running top mass would be correct.

2. When comparing our generated MSSM and NMSSM classes with Softsusy we call calcRunningMtau() and calcRunningMb() in a different way than Softsusy does.  In our cases mw was not correctly set to the running W mass (instead is was set to zero).  For security reasons we think it would be best to explicitely set mw to the running W mass.

Best,
Alex