Fixes for Number isSafeInteger: - use the double version of abs - MAX_SAFE_INTEGER is included
Fixes for Number isSafeInteger:
- use the double version of abs
- MAX_SAFE_INTEGER is included

(port of kdelibs commit 161e956)

KDE/kjs,KDE/kjs,KDE/kjs,KDE/kjs,KDE/kjs,KDE/kjs