wikitext processing tweaks; window height change
new CoolCat category chooser

Includes new GetApi method in MorebitsDotNet, for simple GET accesses to
the API.
transfer of multiple revisions; other refactoring

- Rework of DownloadFileAndDisplayThumb and RevisionBrowse code
- Upload code is substantially reworked
- Vast improvement in warning handling (friendly messages)
- Cryptically named "global variables", like iis, are renamed
- filename => CurrentFilename no longer has the File: prefix
- Use HTTP GET for more stuff
- Get rid of unused "synchoronous" feature in MorebitsDotNet,
  replace it with HTTP method selection
-
add stuff to en.wikipedia.wiki
use greater than symbol for Go link

It was previously a Unicode arrow, but many systems don't seem to be able
to display this correctly for some reason.