Release note updates
Fixed problem with building TW under Windows

Fixes #717

The issue was that under Windows we generate text nodes that contained
CRLF as a linebreak (rather than just LF as usual).

The subtle problem is that when these strings are placed in the DOM via
createTextNode(), the CR character is treated as a printable character,
not whitespace. When creating DOM notes with innerHTML or as part of a
static HTML document the HTML parser will strip out the CR characters.

The hacky solution is to manually remove CRs before building the text
node.
More release note updates
Revert to putting the version number in the corner ribbon

Based on two bits of feedback:

1. The version number should be displayed prominently on the page
2. Ordinary users don’t know what “Find me on GitHub” means
Release note updates
Move editor type mappings into a single file
Fix content type typo
Fix problem with edit widget not refreshing

One symptom of this problem was that changing the type field of a
tiddler didn’t immediately switch to the bitmap editor