Namespace all wpilibc functions/classes into "frc" namespace. (#311)

Base.h provides a backwards compatibility shim (enabled unless
NAMESPACED_WPILIB is defined) that does a "using namespace frc".
However, as some header files do not include Base.h, this may
be a breaking change in some corner cases (with an easy fix).

Fixes #218.

wpilibc/shared/src/Buttons/Button.cpp

@@ -7,6 +7,8 @@
 
 #include "Buttons/Button.h"
 
+using namespace frc;
+
 /**
  * Specifies the command to run when a button is first pressed.
  *

wpilibc/shared/src/Buttons/ButtonScheduler.cpp

@@ -9,6 +9,8 @@
 
 #include "Commands/Scheduler.h"
 
+using namespace frc;
+
 ButtonScheduler::ButtonScheduler(bool last, Trigger* button, Command* orders)
     : m_pressedLast(last), m_button(button), m_command(orders) {}
 

wpilibc/shared/src/Buttons/CancelButtonScheduler.cpp

@@ -10,6 +10,8 @@
 #include "Buttons/Button.h"
 #include "Commands/Command.h"
 
+using namespace frc;
+
 CancelButtonScheduler::CancelButtonScheduler(bool last, Trigger* button,
                                              Command* orders)
     : ButtonScheduler(last, button, orders) {

wpilibc/shared/src/Buttons/HeldButtonScheduler.cpp

@@ -10,6 +10,8 @@
 #include "Buttons/Button.h"
 #include "Commands/Command.h"
 
+using namespace frc;
+
 HeldButtonScheduler::HeldButtonScheduler(bool last, Trigger* button,
                                          Command* orders)
     : ButtonScheduler(last, button, orders) {}

wpilibc/shared/src/Buttons/InternalButton.cpp

@@ -7,6 +7,8 @@
 
 #include "Buttons/InternalButton.h"
 
+using namespace frc;
+
 InternalButton::InternalButton(bool inverted)
     : m_pressed(inverted), m_inverted(inverted) {}
 

wpilibc/shared/src/Buttons/JoystickButton.cpp

@@ -7,6 +7,8 @@
 
 #include "Buttons/JoystickButton.h"
 
+using namespace frc;
+
 JoystickButton::JoystickButton(GenericHID* joystick, int buttonNumber)
     : m_joystick(joystick), m_buttonNumber(buttonNumber) {}
 

wpilibc/shared/src/Buttons/NetworkButton.cpp

@@ -9,6 +9,8 @@
 
 #include "networktables/NetworkTable.h"
 
+using namespace frc;
+
 NetworkButton::NetworkButton(const std::string& tableName,
                              const std::string& field)
     :  // TODO how is this supposed to work???

wpilibc/shared/src/Buttons/PressedButtonScheduler.cpp

@@ -10,6 +10,8 @@
 #include "Buttons/Button.h"
 #include "Commands/Command.h"
 
+using namespace frc;
+
 PressedButtonScheduler::PressedButtonScheduler(bool last, Trigger* button,
                                                Command* orders)
     : ButtonScheduler(last, button, orders) {}

wpilibc/shared/src/Buttons/ReleasedButtonScheduler.cpp

@@ -10,6 +10,8 @@
 #include "Buttons/Button.h"
 #include "Commands/Command.h"
 
+using namespace frc;
+
 ReleasedButtonScheduler::ReleasedButtonScheduler(bool last, Trigger* button,
                                                  Command* orders)
     : ButtonScheduler(last, button, orders) {}

wpilibc/shared/src/Buttons/ToggleButtonScheduler.cpp

@@ -10,6 +10,8 @@
 #include "Buttons/Button.h"
 #include "Commands/Command.h"
 
+using namespace frc;
+
 ToggleButtonScheduler::ToggleButtonScheduler(bool last, Trigger* button,
                                              Command* orders)
     : ButtonScheduler(last, button, orders) {

wpilibc/shared/src/Buttons/Trigger.cpp

@@ -12,6 +12,8 @@
 #include "Buttons/ReleasedButtonScheduler.h"
 #include "Buttons/ToggleButtonScheduler.h"
 
+using namespace frc;
+
 bool Trigger::Grab() {
   if (Get()) {
     return true;