Issue 1: Store items in localStorage with type-based prefix.

With this radicals kanjis and vocabulary with the same character
doesn't get mixt up with each other in localStorage.
Issue 6: Get correct storage key for lessons page.

On lessons the item type is in a separate div and not in
the character character div.
Add sanity checks and don't run the script if they fail.

The sanity check tests that all the elements the script uses
actually exists.
Bump version number.
Issue 2: Add support for radicals during review and lesson quiz
Merge branch 'master' into learning-lookup-support

Conflicts:
	wkhidem.user.js