Reverted a TODO comment from r54429 which disabled the NODE_OPTIONS flag check, so node option buttons could not be disabled at all. This was meant as a workaround to avoid adding do_versions just to set initial NODE_OPTIONS flags on old nodes, but needs a better solution.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57108 954f8c5b-7b00-dc11-b283-0030488c597c
Set the NODE_OPTIONS flag for all nodes by default. If the node type has no options it will be ignored anyway. This makes sure that if options are added to a node type later on there is no need to do a versions patch to update this flag.

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57109 954f8c5b-7b00-dc11-b283-0030488c597c
Remove the NODE_OPTIONS flag usage from node->typeinfo. This is a redundant flag which can be replaced by simply checking for nodetype->uifunc/uifuncbut callbacks (if these callbacks are defined the node
type generally supports options). Note that the node->flag still uses NODE_OPTIONS as a switch to toggle the display of such options!

git-svn-id: https://svn.blender.org/svnroot/bf-blender/trunk/blender@57110 954f8c5b-7b00-dc11-b283-0030488c597c