FEED.PHP should be able to display all posts, not only the most recent

I was used to monitor my favorite forum by only display the RSS feed...

Since FEED.PHP was introduced in 3.0.6, it only displays the last post of every topic, which is pretty unusable for my approach.

I modified the original FEED.PHP by 2 things:
1. A new "mode=posts" which displays all posts while considering any "t=" or "f=" parameters.
2. Introduced a new parameter "num=XXX" to set a user limit for the number of displayed items.

I have to admit, that the second enhancement is still untested and I'm no PHP coder, so there might by some errors or misfunction...