Fixed cpplint.py warnings (#215)

* Fixed cpplint.py [build/include_order] and [build/include_what_you_use] warnings
* Fixed cpplint.py [readability/casting] warnings
* Updated .styleguide format
* Fixed cpplint.py [build/header_guard] warnings

wpilibc/shared/include/Commands/CommandGroup.h

@@ -8,7 +8,9 @@
 #pragma once
 
 #include <list>
+#include <string>
 #include <vector>
+
 #include "Commands/Command.h"
 #include "Commands/CommandGroupEntry.h"
 

wpilibc/shared/include/Commands/PIDCommand.h

@@ -7,13 +7,14 @@
 
 #pragma once
 
+#include <memory>
+#include <string>
+
 #include "Commands/Command.h"
 #include "PIDController.h"
 #include "PIDOutput.h"
 #include "PIDSource.h"
 
-#include <memory>
-
 class PIDCommand : public Command, public PIDOutput, public PIDSource {
  public:
   PIDCommand(const std::string& name, double p, double i, double d);

wpilibc/shared/include/Commands/PIDSubsystem.h

@@ -7,13 +7,14 @@
 
 #pragma once
 
+#include <memory>
+#include <string>
+
 #include "Commands/Subsystem.h"
 #include "PIDController.h"
 #include "PIDOutput.h"
 #include "PIDSource.h"
 
-#include <memory>
-
 /**
  * This class is designed to handle the case where there is a {@link Subsystem}
  * which uses a single {@link PIDController} almost constantly (for instance,

wpilibc/shared/include/Commands/WaitCommand.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <string>
+
 #include "Commands/Command.h"
 
 class WaitCommand : public Command {

wpilibc/shared/include/Commands/WaitForChildren.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <string>
+
 #include "Commands/Command.h"
 
 class WaitForChildren : public Command {

wpilibc/shared/include/Commands/WaitUntilCommand.h

@@ -7,6 +7,8 @@
 
 #pragma once
 
+#include <string>
+
 #include "Commands/Command.h"
 
 class WaitUntilCommand : public Command {