Update en.ini

Addition of missed terms.
Merge pull request #340 from bdcomp/l10n-fixes

Update en.ini
Update app.js

A -> Z sorting of options in Features and Developer tabs (except of the "Developer mode").
Update en.ini

"Sound enabled" is very misleading after disabling this option.
Merge pull request #346 from bdcomp/settings-cleaning

Settings cleaning
Provider list accessibility

Addition of alt text to provider's logos.
Merge pull request #351 from bdcomp/Accessibility

Provider list accessibility
Merge remote-tracking branch 'upstream/dev' into dev