consistent-back-forward: terminate rendering of unneeded requests, keep a small cache of already made requests, fix bug that could cause back/forward + loading to clear screen
warning-on-no-translation: added warning when there is no translation, whether because of source failure or english phrase entered
show-no-definition: indicate that no definition was found when none is found
Merge pull request #12 from antoviaque/consistent-back-forward

consistent-back-forward: terminate rendering of unneeded requests, keep ...
Merge remote-tracking branch 'origin/warning-on-no-translation'
Merge branch 'show-no-definition'

Conflicts:
	static/test/index.test.js
Merge branch 'master' into progress-cursor

Conflicts:
	static/js/adapters/search.js
	static/test/index.test.js

There were some issues with how caching affected the count of whether an in
progress cursor should be displayed.  This merge resolves those conflicts.