Rename RMFT files and references to EXRAIL (#201)

Make naming consistent with our marketing of ex-rail for files and defines

* Rename RMFT.h to EXRAIL.h

* Rename RMFT2.cpp to EXRAIL2.cpp

* Rename RMFT2.h to EXRAIL2.h

* Rename RMFT2MacroReset.h to EXRAIL2MacroReset.h

* Rename RMFTMacros.h to EXRAILMacros.h

* Rename RMFT references to EXRAIL

EXRAIL.h

@@ -0,0 +1,23 @@
+#ifndef EXRAIL_H
+#define EXRAIL_H
+
+#if defined(EXRAIL_ACTIVE)
+ #include "EXRAIL2.h"
+
+  class RMFT {
+    public:
+      static void inline begin() {RMFT2::begin();}
+      static void inline loop() {RMFT2::loop();}
+  };
+
+  #include "EXRAILMacros.h"
+  
+#else 
+  // Dummy RMFT 
+  class RMFT {
+    public:
+      static void inline begin() {}
+      static void inline loop() {}
+  };
+#endif
+#endif