Multi frames render

A script for launche multi instance of nuke render with split frame range for each one.

_____________ v1.1
Replace the commande '-i' by '-x' so the tools doesn't take a nuke_i license but nuke_r ( render license ).

_____________ v1.2

Fix for render multi write node.

# input in your menu.py :

import renderMultiFrame1v2

customPlugin = nuke.menu('Nodes').addMenu('Custom Plugin')
customPlugin.addCommand('render Multi frame', 'renderMultiFrame1v2.main()')