Multiple small fixes

- Turn the planet lighting actions from mixed case to lower case
 - Fix the openspace.rebindKey Lua function which did not work before
 - Fix the openspace.downloadFile function which would fail when not waiting for the the result
 - Rename openspace.walkDirectoryFolder to openspace.walkDirectoryFolders for consistency
 - Remove the openspace.saveLastChangeToProfile function

src/scripting/scriptengine.cpp

@@ -756,10 +756,9 @@ void ScriptEngine::addBaseLibrary() {
             codegen::lua::DirectoryExists,
             codegen::lua::WalkDirectory,
             codegen::lua::WalkDirectoryFiles,
-            codegen::lua::WalkDirectoryFolder,
+            codegen::lua::WalkDirectoryFolders,
             codegen::lua::DirectoryForPath,
-            codegen::lua::UnzipFile,
-            codegen::lua::SaveLastChangeToProfile
+            codegen::lua::UnzipFile
         }
     };
     addLibrary(lib);