#401: Improved design of address object design

I created and pushed a change draft for
 Issue #401 ,  Improved address object design .



https://github.com/oasis-tcs/sarif-spec/blob/master/Documents/ChangeDrafts/Accepted/sarif-v2.0-issue-401-address-rework.docx


  The original design was ambiguous about what
 address.offset  was based on: the parent object, or
 address.baseAddress ?



 We renamed  offset  to
 offsetFromParent  to clear up that ambiguity.
 We removed  baseAddress  because once it s clear that  offset  is based on the parent object, there s no need to duplicate the information in the child object.
 We added some more kind values ( "header" ,
  "table" ) and we (really Michael) made the definitions of
  "section"  and
 "segment"  more precise. We (this time, really me