v0.2 :
  one calibrator class
  x11 gui only
  find ebeam device and sysfs dir
v0.3 :
  xinput2 : device_id, XIevents
v0.4 :
  tuples
v0.5 :
  compute H matrix
  precision option
  test H matrix accuracy
  apply_calibration : driver & evdev
  save/restore cli
v0.6 :
  package name change -> ebeam_tools
  cleanup
v0.7
  clean x11 shutdown (bool is_running)
  final step : show calibration result in gui
  packaging :
  man pages
  icon+desktop file for ebeam_calibrator
  licence cleanup
  fix rpmbuild warnings in calibrator.cpp

v0.8
  handle multiple ebeam device :
    use "Device Node" XIProperty to retrieve eventXX
    associated with each device, and use 
    /sys/class/input/eventXX/device/device/ sysfs dir.
    (XI code based on http://osdir.com/ml/commits.gnome/2011-11/msg00615.html)

v0.9
  add active zone option

v1.0
  sync with module
  switch to tuxfamily.org repo

v2.0
  ebeam_calibrator and ebeam_state use polkit : ebeam-module change sysfs files
    permissions (Since 3.15 kernel, sysfs files can't be world-writable).
  add automatic module insertion and take-over if needed
  add usb ids from https://github.com/dpiquet

TODO :

  kernel/x11 stage 2 "Buttons" ?

  move LL, NUM_POINT to gui

  Rhââââ : xinput input/test.c : get raw data without xi2 XI_RAW...
         see http://www.clearchain.com/blog/posts/xinput-1-xinput-2-conversion-guide 
