More symbol types?

[mbostock]

• [ ] A diagonal cross (saltire)? Or “times” or “ex”? Rename “cross” to “plus”?
• [ ] Left- and right- pointing triangles?
• [ ] Make the diamond square? Separate from “thin diamond” or “rhombus”?
• [ ] An asterisk? Double cross?
• [ ] A (five-pointed) star?
• [ ] A default “triangle” (alias for triangleUp)?

[mbostock]

[mbostock]

Better to have distinct shapes independent of rotation, methinks.