Add halsim_ds_socket to allow a simulated robot to talk to the real DS (#1180)

This implements enough of the UDP and TCP protocol used by the FRC
driver station to allow us to talk to either QDriverStation or to the
real Driver Station.

This was inspired by a similar function in Toast by Jaci, and also
uses a lot of the research found in the QDriverStation project.

simulation/halsim_ds_socket/build.gradle

@@ -0,0 +1,8 @@
+description = "A plugin that listens on a socket so that you can use the real Driver Station software to connect to the simulation"
+
+ext {
+    includeWpiutil = true
+    pluginName = 'halsim_ds_socket'
+}
+
+apply from: "${rootDir}/shared/plugins/setupBuild.gradle"