tiddly_on_tahoe Make the default tiddlywiki indicate capability being used to access it.

[arch_o_median]

I'd like it if I could tell at a glance whether I'm looking at a writeable page, or only a readable page. Zooko's done a nice job of saying this in the SiteTitle??, but I'd like it to be even _more_ obvious. I'm think color a code (even more prominent than the grey background Zooko's also added) would be useful.