[PATCH] Dynamic modes support for PV xenfb (0 of 2)

["Pat Campbell" <plc@novell.com>]

Patches 1of2 and 2of2 adds multiple frame buffer resolution
support to the PV xenfb frame buffer driver and the PV xenfb
VNC server.

API Changelog entry is included here as I did not see doc/ChangeLog
when I did a tip clone this morning.

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API Changelog entry:

 PV framebuffer multiple resolution facility:

  Guest may send XENFB_TYPE_RESIZE if feature-resize = 1 in
  xenstore of the backend VNC server. VNC server code sets
  feature-resize if it can handle the resize reguest.

  When multiple resolution support is enabled the guests frame
  buffer size jumps from 2MB to 5MB.  Maximum scanline length
  is 1280 pixels. Code can support any resolution thats fits
  within the 5MB and does not exceed a width of 1280.

  New xenstore virtual machine specific VNC attributes:
    vncresizable-pvfb: For those that don't need higher
      resolutions in their guest. Default: 0.
    vnc-fixevdev-abs: Older versions of evdev do not
      have an option to disable scaling.  This attribute
      adjust the abs mouse position to counter evdevs scaling.
      Default: 0

  Attribute usage:
    vfb=['type=vnc,vncunused=1,vncresizable-pvfb=1,vnc-fixevdev-abs=1']

  Note: For proper absolute mouse tracking support when
        resizing, the guests xorg.conf file will need to
        have one of the following options added to it's
        InputDevice section.

        For driver 'evdev' add:   Option "AbsoluteScreen" "-1"
         (Or set vnc-fixevdev-abs in the vm config file vfb section)
        For driver 'evtouch" add: Option "Calibrate" "1"

        OpenSuSE 10.3 and Fedora 8 both have evdev AbsoluteSceen
        option.  RHEL5 and SLES10 do not and would require
        vnc-fixevdev-abs.

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Signed-      off-      by: Pat Campbell <plc@novell.com>