Index-aware purging is broken for 3.0

SUBJ.

I've tracked this to a merge:

Author: Filipe David Borba Manana <fdmanana@gmail.com> 2013-08-21 04:39:55
Committer: Filipe David Borba Manana <fdmanana@gmail.com> 2013-08-21 04:39:55
Parent: 5202cfe860d69d7bf4aafa7a1629fe0c4df20912 (Remove unused code initially produced for MB-8689)
Parent: ec6ac751563ac77b252c623f3ad98bcdc52ef32a (MB-8877 Fix builtin reduces for subset development views)
Child: ab3e309a928426c2ae1604b4c107766ef14dddd6 (Merge remote-tracking branch 'origin/2.1.1')
Branches: remotes/couchbase/master, remotes/m/master
Follows: 2.0.0-couchbase, 2.1.1r
Precedes:

Merge remote-tracking branch 'origin/2.1.1'

• origin/2.1.1:
  MB-8877 Fix builtin reduces for subset development views
  MB-8677 Improve test coverage
  MB-8677 Ignore unindexable replicas on transfer set to active
  MB-8780: added compactor option to avoid purging too new seqnos
  MB-8689 Add API to get list of indexed seqs per view group

Conflicts:
src/couch_set_view/src/couch_set_view.erl

Change-Id: I3655f5bad25d178d3a5d29bfa6b838e89fb6a916

ns_server's code expects binary get_indexed_seqs function, while couchdb only has 4-ary.

Some or both sides need to be changed it seems