Add Photonlib (#231)

Merges Photonlib into Photonvision, along with the Photonlib code examples. Also creates a new PhotonTargeting library teams can depend on.

photonlib-cpp-examples/src/main/cpp/examples/aimattarget/include/Robot.h

@@ -0,0 +1,46 @@
+/**
+ * Copyright (C) 2018-2020 Photon Vision.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <photonlib/PhotonCamera.h>
+
+#include <frc/PWMVictorSPX.h>
+#include <frc/TimedRobot.h>
+#include <frc/XboxController.h>
+#include <frc/controller/PIDController.h>
+#include <frc/drive/DifferentialDrive.h>
+#include <units/angle.h>
+#include <units/length.h>
+
+class Robot : public frc::TimedRobot {
+public:
+  void TeleopPeriodic() override;
+
+private:
+  // Change this to match the name of your camera
+  photonlib::PhotonCamera camera{"photonvision"};
+  // PID constants should be tuned per robot
+  frc2::PIDController controller{.1, 0, 0};
+
+  frc::XboxController xboxController{0};
+
+  // Drive motors
+  frc::PWMVictorSPX leftMotor{0};
+  frc::PWMVictorSPX rightMotor{1};
+  frc::DifferentialDrive drive{leftMotor, rightMotor};
+};