related to that cell (since elements are usually temporary and so
kept in a separate list, not in the cell). Corrected a major error
in the bplane implementation that failed to remove a cell use from
the child def's parent list when deleting the use. Can cause magic
to go into an infinite loop, especially after selecting and unselecting
cells.
unrecognized layers when the "readonly" read option is set.
Added support to scale elements (from the "element" command,
such as the measurement text and arrows) when the grid scales,
which was missing. Corrected the output of persistent elements
in a .mag file so that they are correctly scaled by the scale
reducer.