Set working version to 0.6.dev
Make protect_addrinfo noncopyable
Get rid of error throws in po6/threads/...
Merge branch 'master' into releases/0.5

* master:
  Get rid of error throws in po6/threads/...
  Make protect_addrinfo noncopyable
  Set working version to 0.6.dev

Conflicts:
	configure.ac
Set version numbers for 0.5.1 release
Properly wrap IPv6 addrs w/ ports with [] in po6/net
Merge branch 'master' into releases/0.5

* master:
  Properly wrap IPv6 addrs w/ ports with [] in po6/net
Set version numbers for 0.5.2 release