Deprecate SampleRobot (#472)

Suggest TimedRobot as an alternative.

Remove -Werror from examples to avoid breaking build.

wpilibc/src/main/native/include/SampleRobot.h

@@ -7,11 +7,17 @@
 
 #pragma once
 
+#include <support/deprecated.h>
+
 #include "RobotBase.h"
 
 namespace frc {
 
-class SampleRobot : public RobotBase {
+class WPI_DEPRECATED(
+    "WARNING: While it may look like a good choice to use for your code if "
+    "you're inexperienced, don't. Unless you know what you are doing, complex "
+    "code will be much more difficult under this system. Use TimedRobot or "
+    "Command-Based instead.") SampleRobot : public RobotBase {
  public:
   void StartCompetition() override;
 

wpilibj/src/main/java/edu/wpi/first/wpilibj/SampleRobot.java

@@ -22,7 +22,13 @@ import edu.wpi.first.wpilibj.livewindow.LiveWindow;
  *
  * <p>Alternatively you can override the robotMain() method and manage all aspects of the robot
  * yourself.
+ *
+ * @deprecated WARNING: While it may look like a good choice to use for your code if you're
+ *     inexperienced, don't. Unless you know what you are doing, complex code will
+ *     be much more difficult under this system. Use TimedRobot or Command-Based
+ *     instead.
  */
+@Deprecated
 public class SampleRobot extends RobotBase {
 
   private boolean m_robotMainOverridden = true;

wpilibjExamples/build.gradle

@@ -23,7 +23,7 @@ pmd {
 
 gradle.projectsEvaluated {
     tasks.withType(JavaCompile) {
-        options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation" << "-Werror"
+        options.compilerArgs << "-Xlint:unchecked" << "-Xlint:deprecation"
     }
 }