Refactor folder (#10475)

Move many third-party components' source codes from the src folder to a new folder called deps_src. The goal is to make the code structure clearer and easier to navigate.

deps_src/libigl/igl/deprecated.h

@@ -0,0 +1,28 @@
+// This file is part of libigl, a simple c++ geometry processing library.
+// 
+// Copyright (C) 2015 Alec Jacobson <alecjacobson@gmail.com>
+// 
+// This Source Code Form is subject to the terms of the Mozilla Public License 
+// v. 2.0. If a copy of the MPL was not distributed with this file, You can 
+// obtain one at http://mozilla.org/MPL/2.0/.
+#ifndef IGL_DEPRECATED_H
+#define IGL_DEPRECATED_H
+// Macro for marking a function as deprecated.
+// 
+// http://stackoverflow.com/a/295229/148668
+#ifdef __GNUC__
+#define IGL_DEPRECATED(func) func __attribute__ ((deprecated))
+#elif defined(_MSC_VER)
+#define IGL_DEPRECATED(func) __declspec(deprecated) func
+#else
+#pragma message("WARNING: You need to implement IGL_DEPRECATED for this compiler")
+#define IGL_DEPRECATED(func) func
+#endif
+// Usage:
+//
+//     template <typename T> IGL_INLINE void my_func(Arg1 a);
+//
+// becomes 
+//
+//     template <typename T> IGL_INLINE IGL_DEPRECATED(void my_func(Arg1 a));
+#endif