Recognize flag byte in memcache set

[Suhail]

The memcache protocol allows you set a flag byte during a set, kestrel ignores this and defaults it to 0.

Many languages uses a flag to denote the data is serialized so that the client can then deserialize it.

[matterkkila]

Any thought on supporting this in future version?

[robey]

i think it would be difficult to support, but i'll leave this bug open in case others want to vote on it.

[Mistobaan]

I just stumbled upon this error when I tried to use EnymMemcache + Protobuffers. I solved by forcing the client to always deserialize using ProtoBuf