Added 'move' functions to the inputs and outputs node socket collections (similar to move function in CollectionProperty). This is useful to change the socket order in pynodes. Otherwise one would have to remember socket values and links, remove a socket, insert a new one and copy back these values, which is tedious and error prone.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55986 954f8c5b-7b00-dc11-b283-0030488c597c
More fixes for addon i18n messages management.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@55987 954f8c5b-7b00-dc11-b283-0030488c597c