Revert "reload after undo to prevent unit ref weirdness. #118"

This reverts commit 983c645ba9cc333c68c7aef026d8ccf442d5d95a.
Revert "undo button. fixes #118"

This reverts commit 9b0c3e9b4155aac2f582c1bacdfcf85fd2ef7dcb.
changelog
0.2.16