* Update environment info to return the 'safari' browser
* Fix popup display on Safari
* Update environment assignment
* Add data-loading-stalled property when loading takes longer than expected
* Add notification when loading has stalled
* Allow getDictionaryInfo invocation on non-privileged contexts
* Update _validatePrivilegedMessageSender
* Don't listen to 'voiceschanged' event unless addEventListener is present
Also expose an event
* Add double-down-chevron.svg
* Add options
* Update dictionary importers
* Update settings
* Add support for collapsible definitions
* Improve case when there is a very small amount of overflow
* Fix incorrect enabled state of newly imported dictionaries
* Update PopupMenu event prevention
* Use vars for button padding
* Add button-inner-label style
* Add input-button button
* Update display of scope selection
* Add hidden argument text input field
* Remove unnecessary calls
* Display a strike through the enabled button when no scopes are selected