Code quality: Large clean-up of the codebase and especially of the include/ folder

lib/tools/getenv.hpp

@@ -0,0 +1,34 @@
+#ifndef ISAAC_TOOLS_GETENV
+#define ISAAC_TOOLS_GETENV
+
+#include <string>
+
+namespace isaac
+{
+
+namespace tools
+{
+
+    inline std::string getenv(const char * name)
+    {
+        #ifdef _MSC_VER
+            char* cache_path = 0;
+            std::size_t sz = 0;
+            _dupenv_s(&cache_path, &sz, name);
+        #else
+            const char * cache_path = std::getenv(name);
+        #endif
+        if(!cache_path)
+            return "";
+        std::string result(cache_path);
+        #ifdef _MSC_VER
+            free(cache_path);
+        #endif
+        return result;
+    }
+
+}
+
+}
+
+#endif