(#1848) - housekeeping on query() docs

Adds more notes to the db.query()
documentation, especially when we
forgot to mention certain
parameters. Also adds documentation for
options.stale and options.group_level.

The only new code this will require in
order to be accurate is pouchdb/mapreduce#85.
(#1860) - Fix info.doc_count for websql/idb
(#1869) - performance improvements for idb.get

Also includes some generic performance
improvements for merge.traverseRevTree and
utils.isDeleted.
(#1873) - Split out argsarray into its own module
(#1875) - use a library for extend, and then use clone for the 95% of the time where that is what we are using extend for
(#1753) - remove es5 shims
(#1826) - fix level alt going forward
(#1826) - fix level alt going forward
(#1826) - Reremove es5 shim + extend from alt branch
(#1871) - WebSQL total_rows/get performance boosts
(#1887) - Don't leak PouchDB.utils in docs
(#1885) - Only run travis on master + pull requests
(#1878) - pull md5 out and just use a module
(#1883) & (#1842) - split ajax up into 2 parts, also figured out how to do the version thing
(#1843) - Get tests passing on saucelabs
(#1001) - Failed replications calls complete callbacks correctly
(#1564) - Fix check for travis secure vars
(#1853) - make perf tests more accurate for skip/limit

This was accidentally reverted by
fd2a695f4d5ca98dcc8d4f66a2eeabcd437939a6.
(#1859) - Performance tests for map/reduce

Adds performance tests for mapreduce, testing:
* temp views
* persistent views
* persistent views w/ stale=ok