Duplicated exit links in bars [patch included]

[nikai]

There's a small problem in SVN I'm trying to solve: In a number of bars the exit link is duplicated.

In bars on Ocean planets you may not immediately notice, but clicking the right mouse button repeatedly you'll see that the pointer jumps to the exit link twice as often. That's because two links are rendered in the same place.

On desert planets it's most obvious, there are two different texts rendered above each other as the Main Concourse is named Main Tent there. In an other place two exit links are rendered very close to each other, looking weird as well.

So here's an attempt to clean the duplicated links. In order to allow custom exit link text ("Main Tent"), I'm passing that text to MakeBar in bases/bar.py.

[klauss]

Seems like a sensible patch.

Sadly I can't test it ATM, being at work.
But I can commit it. Seems to make sense while reading the patch, so I trust my instincts

I'll test it when I get home.