Stop `edit` from eating entries

Using the `edit` command was eating my entries, so I fixed it (I hope!). This pull request does the following:
- makes colorama optional. Without it, there is no color support on Windows, and the ANSI codes get strangely printed to the output. Fixes Issue #121.
- 'touches' the temp file before writing the old entry to it and opening it. Doing it the other way (at least on Windows) was causing the temp file to be wiped just before it was opened in the editor, and this was wiping the entries. This should be tested with the text editor you were using on your end.
- added better Windows documentation (I can't render RST, so I hope it looks good...)
- documents my changes to the CHANGELOG (and bumps the version number).

Hope this helps!