[feature request] improvement to X-cursor

[gilbertohasnofb]

I think that the current X-cursor does not fit thematically with the rest of the set. Take for instance the original classic theme. Other than the hand cursor, the common cursors are all made out of straight lines at right angles or 45 degrees as well as quarter circles:

The current X-cursor seems to differ substantially from these design ideas:

I think that a simple X would go a long way in unifying the design. Below is an example of how it could look like, this is just the cross cursor rotated 45 degrees. I think it could be thicker than this, but it just gives an idea of how it would be more consistent with the set than the cursor above:

[gilbertohasnofb]

Thank you for implementing this!