**Problem:**
KCL's xLine and yLine functions were telling users to supply either "end" or "endAbsolute" arguments. But "end" is not a valid argument for xLine/yLine, it's actually "length" instead.
**Cause:**
xLine/yLine were using a helper function designed for `line` KCL stdlib functions, which do use `end`.
**Solution**
Add a new param to the helper function, indicating what the label should be for relative lines. "end" for `line` calls, `length` for x/yline
e297f8286f