Renable an assert that the 'z' close command has no arguments.
With the older buggier parser we sometimes ended up with an empty argument, but
with the new parser this should be corrected.  Additionally add a comment
about the close mechanism and a TODO to have a way of marking paths as closed.
Add some tests for l/L lineTo commands, and one with a z close.
Fix a bug in 'M' moveTo handling of additional arguments.
Additional arguments are treated as an L lineTo command.  However we didn't
correctly track curx, cury, so a following relative command could be relative
to the wrong point.
Add a test case for extra arguments on the 'm' moveTo command.
Support multiple arguments for h/H, and support v/V.
Although as the spec mentions it doesn't always make that much sense, but it
does in some cases so there is no reason not to support it.  We could just take
the last point in the list (collapsing everything into a single line), but
perhaps someone wants to be able extract out the original lines.