[UI] Avoid to restore the model graph always when a cell value change

It avoids to loose a lot of time while a model has been infered thanks
to the webservice.
[GRAPH] Update the model graph more often

When criterion state change and when number of categories increase or
decrease the model graph should be updated
[QGIS,GRAPH] Update category colors
[UI] Update the model graph when a XMCDA file is loaded
[MAKEFILE] Add graphic.py and update version number
[GRAPH] Fix small bug

When resetting the number of profiles to 0 there was a division by 0
which is not a good idea...
[UI] Use a gradient of green to represent categories colors
[XMCDA] Invert categories ranks

Categories ranks were inerted in the webservice and in the plugin...
It has been fixed in the webservice and it requires also a change in
the qgis-etri plugin.
[QGIS] Add metadata file
xmcda: fix error in xmcda library formatting the categories

Traceback (most recent call last):
  File "/home/pat/.qgis//python/plugins/qgis_etri/etrimain.py", line 786, in on_Binfer_pressed
    xmcda_data = self.create_xmcda_input()
  File "/home/pat/.qgis//python/plugins/qgis_etri/etrimain.py", line 593, in create_xmcda_input
    xmcda_cats = xmcda.format_categories(cats)
  File "/home/pat/.qgis//python/plugins/qgis_etri/xmcda.py", line 70, in format_categories
    output += "\t\t%d\n" % (ncat-i)
NameError: global name 'ncat' is not defined
ui: change the QMainWindow to a QDialog

This is more logical to have a QDialog box instead of a QMainWindow.
The QMainWindow is the one of qgis.
Moreover it looks to give problem with the last versions of pyqt...
update to v0.3.1
metadata: add author and email
__init__: update metadata
Merge branch 'master' into newui