def files - ensure binary compatibility of 4.7.0 and 4.6.3

We need to make sure 4.6.3 and 4.7.0 are binary compatible with each other.
Probably the way to do this is to merge the 4.7.0 DEF files into 4.6 codeline, with ABSENT added to the new 4.7 API exports, so the ordinals are reserved.
This excercise needs to be repeated for each 4.6 and 4.7 release until the 4.6 codeline is retired.