* Add code to allow each editing window it's own undo/redo count.
* Add code to allow for infinite undo/redo when count is set to 0.
* Add edit control to all editing windows general options dialog for
user configuration of undo/redo count.
* Add code to save and restore undo/redo count for each editing window.
These settings are now not common to the board editor, because the footprint editor can be run outside the board editor.
download_boost.cmake: ignore .htm* files when installing boost. They are not used, and often have a very very long (and stupid) name which sometimes creates issues.
jean-pierre charras
Chris Pavlina
Wayne Stambaugh
Maciej Suminski