XFree86 modes for iMac display are wrong in YDL 2.2

[John & Tina Peterson]

I noticed that control-alt-(keypad)'+' and control-alt-(keypad)'-' didn't
work on my iMac after install.  Checking /etc/X11/XF86Config-4, I noticed
that the dot clock timings looked more like the verical refresh rates than
dot clock times.  Doing a search I found dot clock timings that seem to work
better.  On the mode lines under the 'Apple iMac Display' comment change the
first numbers to:

117 -> 49.886
95 -> 62.357
78 -> 78.525

That last one is for 1024x768.  The numbers are so close (even though one's
in Hz and the other MHz) it works in that mode, but the others are way off.

Now I can zoom in with control-alt-(keypad)'+' and I'm happy.

John Peterson