[wpilibc] Clean up include files (#2708)

Based on run of include-what-you-use.org to identify unused include files in various .h and .cpp files.

The changes mostly fall into 3 categories:
- Actually unused includes - copy-paste errors, not removing includes after cleaning up code, etc
- A too-broad include used where a more specific (and hopefully smaller) header will do
- Interface .h files including headers only needed by the .cpp implementation - moving from .h to .cpp
  will mean that code which uses the .h doesn't pay the price of processing the header file they don't need

wpilibc/src/main/native/include/frc/CAN.h

@@ -10,7 +10,6 @@
 #include <stdint.h>
 
 #include <hal/CANAPITypes.h>
-#include <wpi/ArrayRef.h>
 
 #include "frc/ErrorBase.h"
 

wpilibc/src/main/native/include/frc/DriverStation.h

@@ -16,11 +16,9 @@
 #include <hal/DriverStationTypes.h>
 #include <wpi/Twine.h>
 #include <wpi/condition_variable.h>
-#include <wpi/deprecated.h>
 #include <wpi/mutex.h>
 
 #include "frc/ErrorBase.h"
-#include "frc/RobotState.h"
 
 namespace frc {
 

wpilibc/src/main/native/include/frc/Error.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2018 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2020 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include <stdint.h>
-
 #include <string>
 
 #include <wpi/StringRef.h>
@@ -19,8 +17,6 @@
 #undef GetMessage
 #endif
 
-#include "frc/Base.h"
-
 namespace frc {
 
 class ErrorBase;

wpilibc/src/main/native/include/frc/ErrorBase.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2019 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2020 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -11,9 +11,7 @@
 
 #include <wpi/StringRef.h>
 #include <wpi/Twine.h>
-#include <wpi/mutex.h>
 
-#include "frc/Base.h"
 #include "frc/Error.h"
 
 // Forward declared manually to avoid needing to pull in entire HAL header.

wpilibc/src/main/native/include/frc/Joystick.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2019 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2020 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -9,8 +9,6 @@
 
 #include <array>
 
-#include <wpi/deprecated.h>
-
 #include "frc/GenericHID.h"
 
 namespace frc {

wpilibc/src/main/native/include/frc/RobotState.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2019 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2020 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -7,8 +7,6 @@
 
 #pragma once
 
-#include <memory>
-
 namespace frc {
 
 class RobotState {

wpilibc/src/main/native/include/frc/Timer.h

@@ -7,11 +7,6 @@
 
 #pragma once
 
-#include <units/time.h>
-#include <wpi/deprecated.h>
-#include <wpi/mutex.h>
-
-#include "frc/Base.h"
 #include "frc2/Timer.h"
 
 namespace frc {

wpilibc/src/main/native/include/frc/Utility.h

@@ -1,5 +1,5 @@
 /*----------------------------------------------------------------------------*/
-/* Copyright (c) 2008-2019 FIRST. All Rights Reserved.                        */
+/* Copyright (c) 2008-2020 FIRST. All Rights Reserved.                        */
 /* Open Source Software - may be modified and shared by FRC teams. The code   */
 /* must be accompanied by the FIRST BSD license file in the root directory of */
 /* the project.                                                               */
@@ -11,13 +11,8 @@
  * @file Contains global utility functions
  */
 
-#include <stdint.h>
-
-#include <string>
-
 #include <wpi/StringRef.h>
 #include <wpi/Twine.h>
-#include <wpi/deprecated.h>
 
 #define wpi_assert(condition) \
   wpi_assert_impl(condition, #condition, "", __FILE__, __LINE__, __FUNCTION__)

wpilibc/src/main/native/include/frc2/Timer.h

@@ -8,11 +8,8 @@
 #pragma once
 
 #include <units/time.h>
-#include <wpi/deprecated.h>
 #include <wpi/mutex.h>
 
-#include "frc/Base.h"
-
 namespace frc2 {
 
 /**