skeleton for DSE authentication
SSPI implementation for Kerberos
Kerberos support
merged with master untested
merged with master untested
Merge branch 'dse_3.1' of https://github.com/datastax/csharp-driver into dse_3.1
Merge branch 'master' into dse_3.1

Conflicts:
	Cassandra/Cassandra.csproj
	Cassandra/CassandraConnection.cs
	Cassandra/Session.cs
	Playground/Program.cs
prepare for merged version tests
Merge remote-tracking branch 'remotes/origin/dse_3.1' into 1.0