Move over remaining issues from trac

So we're going to start using github's issue tracking system. This means we need to bring over open issues from trac. We might want to do a shakeout and reexamine or reformulate existing issues along the way.

Here's a full list of issues on the Helma trac:  
https://dev.helma.org/trac/helma/report/6

And of course, keep those new issues coming.
