Note that this only works where a BOARD_COMMIT or SCHEMATIC_COMMIT is used.
(BOARD_COMMIT is used almost universally in PCBNew, but SCHEMATIC_COMMIT
has very little adoption in EEschema so far.)
Provides a single-point access for modifying the schematic and symbol
elements that allows chaining updates and reverting partial changes.
Standardizes the undo hierarchy between pcb and schematic editors
As this is another layer on the existing undo/redo structure, the
initial commit does not replace all undo/redo calls currently existing.
These will be handled in a series of follow-on commits
Jeff Young
Marek Roszko
Seth Hillbrand