Merge branch '301-show-session-description-in-the-view-of-a-lecturer-without-menu-and-title' into 'master'

Resolve "Show session description in the view of a lecturer without menu and title"

Closes #301

See merge request !259

wording

See merge request arsnova/arsnova-lite!256

wording and spelling

See merge request arsnova/arsnova-lite!255

Fix service worker

Closes #299

See merge request arsnova/arsnova-lite!254

correct some manifest settings

See merge request arsnova/arsnova-lite!253

wording and spelling

See merge request arsnova/arsnova-lite!252

wording and spelling

See merge request arsnova/arsnova-lite!251

"create question" and "statistics" commented out for EDULEARN19

See merge request arsnova/arsnova-lite!249

some style edits

See merge request arsnova/arsnova-lite!248

Resolve "Hide "Ask question" and "Statistics" options"

Closes #293

See merge request arsnova/arsnova-lite!246

Merge branch '297-f-ed-up-design-on-the-light-version-when-focusing-on-any-input-field' into 'master'

Fix colors in several components

Closes #297

See merge request arsnova/arsnova-lite!247

Resolve "Show local time in header"

Closes #246 and #245

See merge request arsnova/arsnova-lite!240

adjust some settings

See merge request arsnova/arsnova-lite!245

revise Manifest

See merge request arsnova/arsnova-lite!244

Update room-participant-page.component.scss

See merge request !243

Update room-creator-page.component.scss

See merge request arsnova/arsnova-lite!242

Update content-list.component.scss

See merge request arsnova/arsnova-lite!241

Update present-comment.component.scss

See merge request arsnova/arsnova-lite!239

Update comment.component.scss

See merge request arsnova/arsnova-lite!238