vcs Support 0.5.3

I've had to release vcs Support version 0.5.3 to correct a bug where alarms were always imported as "0 days after the event starts". It's still not perfect, but it's better than it was. The problem is actually a problem with Sunbird and Lightning, which don't process alarms with absolute times properly, so an ugly hack was needed. Anyway, it's available from AMO as usual at:

https://addons.mozilla.org/en-US/thunderbird/addon/4721

It's still in the sandbox, by the way, so you'll need to register with AMO to get it.