This has the following known shortcomings:
 - It doesn't handle missing events not in the from/to range.
 - It doesn't order events in the timeline correctly.
 - It doesn't handle invited/left rooms at all.
 - There is no intelligent wakeup logic: events for Bob will wake up Alice's stream.

Also ensure every sync response has a `next_batch` token by forcing
it in the constructor, as previously timeouts would not have a token.

Currently the HTTP handlers are attached to an API mux which is created inside
Setup(). In the future, we'll want to split this out so a single mux can have
both sync and clientapi handlers attached to it.

This distinguishes them from tools like 'kafka-producer'
which are not required to run a dendrite server.

The prefix also groups together the dendrite binaries nicely
on `ls` as well as making it nicer to tab-complete.

* Update gomatrixserverib dep

* Use helper functions when creating rooms

* Use gomatrixserverlib.StateKeyTuple

* Add option to stop processing input after a given number of messages

* Implement state conflict resolution

This involves:
 - Parsing the HTTP request
 - Requesting auth events from the roomserver via the Query API
 - Building the event
 - Doing auth checks on the event
 - Sending it to the roomserver input log

* Tool for creating room events

Previously, the error responses:
 - were not valid matrix errors (no `errcode`)
 - returned the `err.Error()` message which may contain sensitive information.
 - did not get logged (at all, let alone set the level correctly).

Now the error responses:
 - return valid matrix errors (`M_UNKNOWN`)
 - return a generic "Internal Server Error" string
 - get logged at `ERROR` level.

* Return the requested portions of current state in the query API

* Use Unique from github.com/matrix-org/util

* rewrite bulkSelectFilteredStateBlockEntries to use append for clarity

* Add test for stateKeyTupleSorter

* Replace current with a new StateEntryList rather than individually setting the fields

This should:
    1) Make the input package a bit cleaner.
    2) Allow use to reuse the state reading code from the query package.

* Update github.com/matrix-org/util

* Use Unique from github.com/matrix-org/util