v0.7.68

• [web] UI updates to the layers menu, sidebar tabs and arrow menu.
• [web] Changed the console prompt from $ to >.
• A map frame fitted to visible layers now makes room for the rendered size of symbols and labels (these could previously be cut off at the edges of the frame). Add ignore-symbols to -frame to fit to point locations as before.
• The line-height label style now treats a bare number as a multiple of the font size, as in CSS (e.g. line-height=1.3). Previously a bare number was read as pixels; add px to use pixels (e.g. line-height=16px).