Revert "Changelog for #466 and #468"

This reverts commit bcb16de02bb3a6cbf1797bfd3f7d56022203b854.
Add a new test file to hold the viewport tests, and a few new tests to it.
Add viewport.js to test.html so tests get run. Use built-in Point functions. Add a helper function to get a random number.
Added Gitter badge
Use propEqual to verify Point values, add a stub test for imageToWindowCoordinates
add test for windowToImageCoordinates
Merge remote-tracking branch 'origin/master' into viewport-tests
imageToViewerElementCoordinates and imageToWindowCoordinates
viewerElementToImageCoordinates
Merge pull request #501 from gitter-badger/gitter-badge

Add a Gitter chat badge to README.md
Fix a bad merge of changelog.txt
Merge remote-tracking branch 'origin/master' into viewport-tests
Take out multiplication to avoid precision errors because it doesn't; add viewportToImageRectangle test
Force a zoom factor of 2 and make that a constant; find the viewer position in the window for imageToWindowCoordinates (still not sure where the 20 x 20 pixel padding is coming from
More constants, fewer magic numbers.
Remove randomness from test cases.
Replace more magic numbers with constants.
Incorporate code review feedback, add a times method to the Rect class.
Merge pull request #506 from nein09/viewport-tests

Viewport tests - here's what I have so far.
Merge branch 'master' into collections

fixed Conflicts:
	test/test.html