Upgrade to cohttp-0.11.2

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>
Merge pull request #2 from jonludlam/cohttp-0.11.2

Upgrade to cohttp-0.11.2
Merge tag '0.10.1'

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>

Conflicts:
	core/protocol_unix.ml
0.10.2 release

Signed-off-by: Jon Ludlam <jonathan.ludlam@citrix.com>
Merge pull request #3 from jonludlam/0.10.2

0.10.2