Addressed issues found by Google code lint.

Fixed:
 - Removed trailing whitespace.
 - Removed out of date TODO's.
 - Added #include<algorithm> to DataManager.cpp
 - Reordered includes to include C system headers before C++ system headers.
 - Added username to TODO's
 - Renamed include guards to use full project name as prefix.
 - Made methods and parameters const where possible.
 - Made UDPSocket constructor explicit.

Won't Fix:
 - snprintf is introduced in C++11.
 - Trailing comments at the end of namespace & header guards
 - Did not re-inlude headers already included by the matching XPC header.
 - localtime is fine since X-Plane is not multithreaded at all on the plugin side.
 - Linter confuses #elif with parens as a function call.
 - namespace indentation

xpcPlugin/Drawing.h

@@ -1,7 +1,7 @@
 //Copyright (c) 2013-2015 United States Government as represented by the Administrator of the
 //National Aeronautics and Space Administration. All Rights Reserved.
-#ifndef XPC_DRAWING_H
-#define XPC_DRAWING_H
+#ifndef XPCPLUGIN_DRAWING_H_
+#define XPCPLUGIN_DRAWING_H_
 
 #include <cstdlib>