distinguish between lower and upper key
readme typo, gitignore tests folder
forgot to mention graphicsmagick
refactor, comment, new behavior after recording

Make browser restart rather than refresh upon recording and before
playback. Basically, trigger (`_playbackTaskAndSaveScreenshot`) after recording
specification for our dear windows users
remove gm dependency

Only used for comparing image diffs. Inlined the code.
bump version, add changelog