cyrus-imapd-3.0 branch created

[ellie timoney]

Hi,

I've created the cyrus-imapd-3.0 branch.  Fixes and stuff that need to
be in 3.0.x releases should be applied or backported to here.

The master branch is now what will eventually become the 3.1 series. 
Issues affecting this branch specifically should be labelled "3.1" on
github.

(There's still some website infrastructure fiddling to be done.  Will
sort this out once the next 3.0.0 release candidate is up, sometime this
afternoon.)

Cheers,

ellie