add second argument to usb_acknowledge.
it can be used for more appropriate connection tracking that does not
rely on timeout in the future.
Change-Id: I8a44366b7c7a1f944524c4ba8ecd6d9673746a65
Screenshots of the recovery menu will be useful for documentation.
This can be disabled by turning off HAVE_BOOTLOADER_SCREENDUMP in
the target config file if the bootloader should ever run up against
max size limits.
Change-Id: I62ec1e465df2ca7a8a0e78625d88b31f6c4ef078
