Jemi progress, part 5

I felt pretty awful after my Covid vaccination, so I spent a lot of time sitting in bed working on Jemi.

I added handling for all the error responses; view source; user-selectable font; remember size, position and zoom; fixed link bugs (I think); fixed reading badly formatted response headers; fixed the default page so it's gemini text and in the history; fixed cache bug (nothing ever timed out)

Bug list: no wait cursor after clicking a link; not handling external links (HTTP, etc); non-text responses... should what? (hmm - some other clients allow you to display an image link in line...)
Feature requests: bookmarks; context menu; visited link colour; user-defined colours; gopher protocol, because it's a piece of cake