Instead of having files foo.html "in front of" foo/, I prefer to have foo/index.html. This patch allows that. Specifically, foo/index.type is translated to $links{'foo/'}, and bestlink looks for either "foo" or "foo/" when linking to pages. There are other miscellaneous changes that go with that:
1. change the `cgi_editpage` `@page_locs` code so that creating foo from a/b/c prefers a/b/foo and then a/b/c/foo, but if creating foo from a/b/c/, then prefer a/b/c/foo. I'm not really sure why the original was doing what it did (why trim terminal `/` if no pages end in `/`?), so this part might break something.
2. backlinks from "foo/bar" to "foo/" trim common prefixes as long as there would be something left when the trimming is done (i.e. don't trim "foo/")
3. parentlinks for "foo/" are the same as for "foo", except one directory higher
4. rewrite parentlinks so that bestlink is called at each level
5. basename("foo/") => basename("foo")
6. links to "foo/" are translated to "foo/index.html" rather than "foo/.html". (Links to "foo/" might be preferred, but that causes an infinite loop in writefile, because apparently dirname("foo/") == "foo/" on my system for reasons that aren't clear to me.)
In case whitespace gets garbled, I'm also leaving a copy of the patch on [my site](http://ikidev.betacantrips.com/patches/index.patch). It should apply cleanly to a freshly unpacked ikiwiki-1.40. You can also see it in action [here](http://ikidev.betacantrips.com/one/). --Ethan
