Map Grids: fixed the strange l2 placement of labels and their orientation.  Allowed corner labels to override labels which they overlap with.  Fixed some pixel alignment issues, especially regarding putting the border outside of the image and having the text adjust accordingly.  Assuming nothing turns up in error testing it's ready to go.  With the exception, of course,  that the preferences page still needs to be updated.  But this will emulate the layer editor page.  So once we have reviewed this,  we can then update the preferences page which can be fairly easily written.