Minecraft 1.6.4 updates

Updating SS to support 1.6.4 clients. It appears that the only change between 1.6.2 and 1.6.4 in terms of the protocol is simply the version number.
Merge pull request #312 from ginbot86/patch-4

Minecraft 1.6.4 updates
force a JRE6 compatible build
version bump for MC 1.6.4
fixes #307
[skip] redundant toString()
fixes #309
Merge pull request #4 from SimpleServer/master

Pull from SimpleServer