allDocs(startkey, endkey) is slow because it counts every document every time

[dholth]

Related to #27 I noticed an allDocs() query from a database with 5500 documents was taking 12 seconds. The result includes the rows fetched and the total number of rows in the database. Removing the total number of rows from the query seemed to speed things up significantly. I think the majority of the time was spend counting the documents I didn't fetch. This slowness affects info() as well. Am debating whether to patch around, fix, or switch to wkwebview + indexeddb on iOS.