Undo keeps you open-minded to the possibility you can ruin everything, and always get it back, so you won't be scared of failure, but keep trying.
Undo is the fail-safe, the backup-storage, the 80's-print outs, the 90's diskette.
In short; Don't Panic (The Hitchhiker's Guide to the Galaxy).
Me, Just Now.. (March 2014)
Increase Undo (CTRL+Z) to any number from
default limit of 100 actions per-file and 10 global sets.
you can also add global variable to your JAVA_OPTION
or to your webstorm.exe.vmoptions (or idea.exe.vmoptions)
there are other configurations
might be useful like: