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/include/SmartDashboard/NamedSendable.h

@@ -11,6 +11,8 @@
 
 #include "SmartDashboard/Sendable.h"
 
+namespace frc {
+
 /**
  * The interface for sendable objects that gives the sendable a default name in
  * the Smart Dashboard
@@ -24,3 +26,5 @@ class NamedSendable : public Sendable {
    */
   virtual std::string GetName() const = 0;
 };
+
+}  // namespace frc

wpilibc/shared/include/SmartDashboard/Sendable.h

@@ -12,6 +12,8 @@
 
 #include "tables/ITable.h"
 
+namespace frc {
+
 class Sendable {
  public:
   /**
@@ -31,3 +33,5 @@ class Sendable {
    */
   virtual std::string GetSmartDashboardType() const = 0;
 };
+
+}  // namespace frc

wpilibc/shared/include/SmartDashboard/SendableChooser.h

@@ -14,6 +14,8 @@
 #include "SmartDashboard/Sendable.h"
 #include "tables/ITable.h"
 
+namespace frc {
+
 /**
  * The {@link SendableChooser} class is a useful tool for presenting a selection
  * of options to the {@link SmartDashboard}.
@@ -44,3 +46,5 @@ class SendableChooser : public Sendable {
   std::map<std::string, void*> m_choices;
   std::shared_ptr<ITable> m_table;
 };
+
+}  // namespace frc

wpilibc/shared/include/SmartDashboard/SmartDashboard.h

@@ -17,6 +17,8 @@
 #include "SmartDashboard/Sendable.h"
 #include "tables/ITable.h"
 
+namespace frc {
+
 class SmartDashboard : public SensorBase {
  public:
   static void init();
@@ -94,3 +96,5 @@ class SmartDashboard : public SensorBase {
    */
   static std::map<std::shared_ptr<ITable>, Sendable*> m_tablesToData;
 };
+
+}  // namespace frc