Allow converting in opposite order

[JeremySorensen]

It would be super helpful to have a second menu option to convert case in the opposite of the order set in options. So if the order was such that invoking the standard command would convert an identifier in camelCase to PascalCase, then invoking the alternate command on an identifier in PascalCase would convert it to camelCase in 1 step instead of having to loop around.
It could be bound to Ctrl+Shift+K, Ctrl+Shift+U for symmetry with the comment commands by default.