Fix fold reduce with non-inclusive end key
Fix fold reduce with non-inclusive end key

Fold reducing a btree with with end_key_gt was not producing
the correct values. For example, for view queries with startkey
and starkey_docid and/or endkey and endkey_docid and inclusive_end
set to false, the doc ID component of the view keys was not
respected.
Example query:

http://server:5984/db/_design/test/_view/myview?startkey=4&endkey=6&endkey_docid=5&inclusive_end=false

Closes COUCHDB-1413

fkaempfer/couchdb,KlausTrainer/couchdb-couch,apache/couchdb-couch,KlausTrainer/couchdb-couch,cloudant/couchdb-couch,smithsz/couchdb-couch,alanning/couchdb-couch,fkaempfer/couchdb,fkaempfer/couchdb,smithsz/couchdb-couch,cloudant/couchdb-couch,apache/couchdb-couch,cloudant/couchdb-couch,fkaempfer/couchdb,KlausTrainer/couchdb-couch,ngpestelos/couchdb-couch,ngpestelos/couchdb-couch,alanning/couchdb-couch,apache/couchdb-couch,smithsz/couchdb-couch,fkaempfer/couchdb,ngpestelos/couchdb-couch,alanning/couchdb-couch,fkaempfer/couchdb