Update LiveWindow to provide continuous telemetry. (#771)

LiveWindow.updateValues() is now called from IterativeRobotBase on every
loop iteration.  Telemetry for all WPILib classes is enabled by default;
it can be disabled for specific classes using LiveWindow.disableTelemetry(),
or all telemetry can be disabled using LiveWindow.disableAllTelemetry().

This necessitated changing the hook methodology into other classes to
be more property-based rather than each class providing multiple functions.
This had the benefit of reducing boilerplate and increasing consistency.

- Remove NamedSendable, add name to Sendable.

- Provide SendableBase abstract class.

- Deprecate LiveWindow addSensor/addActuator interfaces.

- Add LiveWindow support to drive classes.

- Add addChild() helper functions to Subsystem.

- Fix inheritance hierarchy.  Now only sensors inherit from SensorBase.
  Other devices inherit from some combination of SendableBase, ErrorBase, or
  nothing.

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

@@ -7,14 +7,9 @@
 
 #pragma once
 
-#include <memory>
-#include <string>
-
 #include <HAL/Types.h>
 
-#include "LiveWindow/LiveWindowSendable.h"
 #include "SolenoidBase.h"
-#include "networktables/NetworkTableEntry.h"
 
 namespace frc {
 
@@ -25,23 +20,19 @@ namespace frc {
  * The DoubleSolenoid class is typically used for pneumatics solenoids that
  * have two positions controlled by two separate channels.
  */
-class DoubleSolenoid : public SolenoidBase, public LiveWindowSendable {
+class DoubleSolenoid : public SolenoidBase {
  public:
   enum Value { kOff, kForward, kReverse };
 
   explicit DoubleSolenoid(int forwardChannel, int reverseChannel);
   DoubleSolenoid(int moduleNumber, int forwardChannel, int reverseChannel);
-  virtual ~DoubleSolenoid();
+  ~DoubleSolenoid() override;
   virtual void Set(Value value);
   virtual Value Get() const;
   bool IsFwdSolenoidBlackListed() const;
   bool IsRevSolenoidBlackListed() const;
 
-  void UpdateTable();
-  void StartLiveWindowMode();
-  void StopLiveWindowMode();
-  std::string GetSmartDashboardType() const;
-  void InitTable(std::shared_ptr<nt::NetworkTable> subTable);
+  void InitSendable(SendableBuilder& builder) override;
 
  private:
   int m_forwardChannel;  // The forward channel on the module to control.
@@ -50,9 +41,6 @@ class DoubleSolenoid : public SolenoidBase, public LiveWindowSendable {
   int m_reverseMask;     // The mask for the reverse channel.
   HAL_SolenoidHandle m_forwardHandle = HAL_kInvalidHandle;
   HAL_SolenoidHandle m_reverseHandle = HAL_kInvalidHandle;
-
-  nt::NetworkTableEntry m_valueEntry;
-  NT_EntryListener m_valueListener = 0;
 };
 
 }  // namespace frc