Issue #2382561 by Sabreena, DickJohnson, aliyakhan, Tom Verhaeghe, emma.maria: In narrow viewports (<320px), the toolbar menu tray should be 100% width

Issue #2422363 by mortendk, joelpittet, davidhernandez: Rewrite the menu CSS components inline with our CSS standards

Issue #2409427 by joelpittet, SteveK, sivaramakrishnan, skippednote, idebr: Toolbar vertical orientation link not expanding to fill the space

Issue #1855066 by Tom Verhaeghe, Wim Leers, benjifisher: In the "menu" toolbar tray, clicking/tapping white space should show the child level

Issue #1963886 by ry5n, jessebeach, dcrocks, Wim Leers: Use HiDPI icons in the toolbar to support scaling on different devices.

Issue #1938044 by hass, jessebeach, Dragan Eror: Fixed Prefix all toolbar classes to prevent theme clashes.

Issue #2015789 by fubhy, echoz, rteijeiro, LewisNyman, penyaskito: Remove language_css_alter() (RTL stylesheets) in favor of HTML 'dir' attribute.

Issue #1137920 by jessebeach, lewisnyman, tkoleary, Bojhan, webchick, benjifisher, nod_, sjbassett, kathryn531, effulgentsia, Everett Zufelt: fixed toolbar on small screen sizes and redesign toolbar for desktop.