Added approximation for POSIX expm1() function for MSVC compilers
Added approximation for POSIX expm1() function for MSVC compilers

hrobeers/qxtweb-qt5,hrobeers/qxtweb-qt5,mmitkevich/libqxt,hrobeers/qxtweb-qt5,mmitkevich/libqxt,mmitkevich/libqxt,hrobeers/qxtweb-qt5,mmitkevich/libqxt,hrobeers/qxtweb-qt5