count_daily_users failed if db was sqlite due to type failure - presumably this prevcented all sqlite homeservers reporting home

Add Cache-Control headers to all JSON APIs

404 correctly on missing paths via NoResource

fixes https://github.com/matrix-org/synapse/issues/2043 and https://github.com/matrix-org/synapse/issues/2029

Use .iter* to avoid copies in StateHandler

It is especially important that sync requests don't get cached, as if a
sync returns the same token given then the client will call sync with
the same parameters again. If the previous response was cached it will
get reused, resulting in the client tight looping making the same
request and never making any progress.

In general, clients will expect to get up to date data when requesting
APIs, and so its safer to do a blanket no cache policy than only
whitelisting APIs that we know will break things if they get cached.

Fix replication after switch to simplejson

rearrange ordering of releases to match chronology

Turns out that simplejson serialises namedtuple's as dictionaries rather
than tuples by default.

bump version

Fix bug where state cache used lots of memory