- add hw/xfree86/utils/cvt/, cvt.c, cvt.man.pre and Makefile.am.
- Adjust configure.ac and hw/xfree86/utils/Makefile.am for cvt.
- Add MonPtr->reducedblanking and Option "ReducedBlanking" to the Monitor
section.
- Check for reduced blanking in xf86CheckModeForMonitor and disallow modes
with less than 25% blanking otherwise.
- Fix some warnings in hw/xfree86/common/xf86Config.c.