turn --disable-registration into --enable-registration, given the default is for registration to be disabled by default now. this is backwards incompatible by removing the old --disable-registration arg, but makes for a much more intuitive arg

This reverts commit ff1fa0fb.

Allow registration in the HSes federation demo

Application services transaction reliability (PR #106)

Conflicts:
	synapse/storage/__init__.py

Remember the 'last seen' time for a given user/IP/device combination and only bother INSERTing another if it's stale

Store rearrangement

Add the tiniest of tiny one-element caches to get_room_events_max_id() as it's read every time someone hits eventstream

Allow @cached-wrapped functions to have more or fewer than 1 argument; assert on the total count of them though

Hotfixes v0.8.1 r2

Disable registration by default. Add script to register new users.