Branch: rosuav/hilfe-improvements

Two smallish improvements to Hilfe. One is suppressing "quit" and "exit", per the TODO at the top; fairly simple but I'd like someone else's eyeballing to make sure it's going about things the right way.

The other is the addition of a new help() built-in function, which gives human-readable information about whatever object it's given. Currently it shows a little information about functions and programs, and not much else; the intent is that it can be expanded at will, since it's purely human-readable. There is no backwards-compatibility guarantee about its specific output format.

There's nothing particularly invasive about either of these changes, but I'd appreciate someone else's view on the code before it gets merged.

Thanks!

ChrisA