Unify syntax

[enzet]

Lines, circles, and rectangles work differently:

• lines have two commands for filled and not filled style: lf, l,
• circles have no stroke and always filled,
• rectangles have stroke and always filled.

The goal is to make unified commands: l for lines, e for circles, and r for rectangles, and add one more command: fill. So, lf should now be fill with l command, old e should be w 0 and fill with e, old r should be fill with r.