Changed videocap to recording in modifyvm and controlvm, changed from
usb to usbohci in modifyvm command, added new movevm and mediumio
commands and cloud related options.
VBoxManage removed "debug" from list of commands in help, leaving only
description for "debugvm" in section "Introspection and guest debugging"
below all of the list, so that it is needed for adding "debugvm" to the
list of available commands manually.
Also "stack", new subcommand was added to "debugvm".