minor tweaks to Following plugin
minor tweaks to Following plugin

* cdent suggested using AND tag:follow rather than ;select=tag:follow for performance
improvements
* fixed bug that was making reply button show up in activity feed rather than
tiddler.

TiddlySpace/tiddlyspace,FND/tiddlyspace,TiddlySpace/tiddlyspace,FND/tiddlyspace,TiddlySpace/tiddlyspace,FND/tiddlyspace