Changes and enhancements on audio, wIP

bigbluebutton-html5/imports/api/audio/client/bridge/sip.js

.../imports/ui/components/audio/audio-controls/component.jsx

.../imports/ui/components/audio/audio-controls/container.jsx

...l5/imports/ui/components/audio/audio-controls/styles.scss

...ml5/imports/ui/components/audio/audio-modal/component.jsx

...html5/imports/ui/components/audio/audio-modal/styles.scss

.../imports/ui/components/audio/audio-settings/component.jsx

...html5/imports/ui/components/audio/echo-test/component.jsx

...n-html5/imports/ui/components/audio/echo-test/styles.scss

...tton-html5/imports/ui/components/audio/help/component.jsx

...button-html5/imports/ui/components/audio/help/styles.scss

...rts/ui/components/audio/permissions-overlay/component.jsx

...ports/ui/components/audio/permissions-overlay/styles.scss

bigbluebutton-html5/imports/ui/components/audio/service.js

...uebutton-html5/imports/ui/components/dropdown/styles.scss

...uebutton-html5/imports/ui/services/audio-manager/index.js

bigbluebutton-html5/imports/ui/services/auth/index.js

...ebutton-html5/imports/ui/stylesheets/variables/focus.scss

bigbluebutton-html5/private/locales/en.json