- Corrected problem in unit test that expected the wrong result.
- Fixed Color::Color (const std::string&) so that the foreground and
background are now considered two different colors, are upgraded
separately, if necessary, and then blended. The problem affected
all instances of "<256-color> on <16-color>". Hooray for unit
tests.
- Oddly, there were no unit tests for the Color object. Now there are
1,033.
- Three of these tests fail, which justifies adding them in the first place.
