[ros-diffs] [fireball] 33139: - Add more MDL flags. - Reformat MDL implementation (mdlsup.c) to make it readable, and add comments. - Add a couple dozen assertions to validate that MDL flags, state and addresses. - Use ADDRESS_AND_SIZE_TO_SPAN_PAGES macro for nice MDL calculations. - Set Mdl->Process only when required, and set/unset various MDL flags which were being ignored/incorrectly manipulated. - Keep track of Process->NumberOfLockedPages during MDL lock/unlock. - Don't return the base address of the