Update version number for 0.3.1
Update version number for 0.3.2
Use webkit-any to make CSS match more situations
Update deprecated API calls

onRequest and sendRequest deprecated in v20
Treat canvas objects as images

Do not invert canvas objects in smart invert mode.
Branch for release 0.3.2
Merge branch 'release-0.3.2'

Changelog
  * Recognize canvas objects as images
  * More consistently recognize images
  * Update Chrome API calls