Began implementing a proper shutdown sequence. It's incomplete.
Revert "Began implementing a proper shutdown sequence. It's incomplete."

This reverts commit 908395db6cbc627596dfce4fc07762bfe2780d21.
Proper shutdown handling for threaded coroutines.
Merge branch 'next' into daniel_2168
Removed an unnecessary header.
Update performance regression with the new cache_size + add some cool stuff
Add ifdefs to make this compile without THREADED_COROUTINES
Add commits + clean stuff
Copy the jquery file from admin/static/js
Clean duration for batch insert + add comment
Merge branch 'michel_2072_perf_test2' into next
Merge branch 'daniel_2168' into next
Merge branch 'next' of github.com:rethinkdb/rethinkdb into next
Make two_level_nevershrink_array_t chunk size consistent with two_level_array_t chunk size.
Make two_level_nevershrink_array_t chunk size consistent with two_level_array_t chunk size.
Merge branch 'v1.12.x' into next
Merge branch 'next' into sam_803
Merge branch 'sam_803' into sam_803_dummy