implemented the rest of the functions on the "posts" page; fixed post links

so they work now; added the HTML Reference (originally from CW); added the
post output filtering to turn the "pseudo-URIs" in the database into real
URIs

TODO

@@ -25,19 +25,6 @@ Lots!
   statements in the case of joined queries (no need to SELECT table.column
   AS name).
 
-- Functions still to do on conferencing "posts" page:
-  Hide/Show Topic
-  Next & Keep New (make it actually Keep New)
-  Freeze/Unfreeze Topic
-  Archive/Unarchive Topic
-  Delete Topic
-  Make number of "viewable" posts per page a config option
-  Display the message locator (i.e. <Playground.56.123>) above each message
-  Hide/Show Post
-  Scribble Post
-  Nuke Post
-  Put the HTML Guide in (for all pages w/post boxes)
-
 - Slippage during posting is still untested.
 
 - Functions still to do on conferencing "topics" page: