Hook for modifying the similar nodes

I propose that the nodes array should be passed to a hook so that other modules can modify it. This arises from my need to modify the list in a way that is too customised to warrant making specific admin options.

The following code should do it. Patch attached.

// Allow modules to alter the list of nodes by implementing a hook.
// TODO: Pass by reference the $nodes array rather than returning them.
$nodes = module_invoke_all('similarterms_alter', $node_obj, $nodes);