We had lots of hard-coded logic to do slightly different things
depending on which version of a particular field was present in a
schema. For every field that has now been completely removed, we can
remove references including these bits of extra logic.
The difference is especially striking in the sortkey query path. Note
that queries containing sortkeys have already been failing since
servers upgraded to schema version 8 (2.9), which no longer uses this
field.
Change-Id: Ib1fbc9f3aa45bf068b7869ca3aada40dbe4cb1bb
90ee0cb3f2