Added LIBPATH to fix linux build (#1536)

* Added LIBPATH to fix linux build

* added -std=c++14 to osx

tutorials/plugins/gdnative/files/cpp_example/SConstruct

@@ -19,7 +19,7 @@ def add_sources(sources, directory):
             sources.append(directory + '/' + file)
 
 if platform == "osx":
-    env.Append(CCFLAGS = ['-g','-O3', '-arch', 'x86_64'])
+    env.Append(CCFLAGS = ['-g','-O3', '-arch', 'x86_64', '-std=c++14'])
     env.Append(LINKFLAGS = ['-arch', 'x86_64'])
 
     final_lib_path = final_lib_path + 'osx/'
@@ -38,7 +38,8 @@ elif platform == "windows":
     final_lib_path = final_lib_path + 'win' + str(bits) + '/'
 
 env.Append(CPPPATH=['.', 'src/', "godot_headers/", 'godot-cpp/include/', 'godot-cpp/include/core/'])
-env.Append(LIBS=["godot-cpp/bin/godot-cpp" + "." + platform + "." + str(bits)])
+env.Append(LIBPATH="godot-cpp/bin")
+env.Append(LIBS=["godot-cpp" + "." + platform + "." + str(bits)])
 
 sources = []
 add_sources(sources, "src")