Merge pull request #1921 from bfroehle/_1890_magic_arguments_docstring magic_arguments: dedent but otherwise preserve indentation. Previously magic_arguments stripped all whitespace at the beginning of each line, interfering with formatting syntax which relies on indentation to give context (e.g., code blocks). Now the docstring text is passed through dedent to strip the global indentation before being handed off to `RawDescriptionHelpFormatter` which preserves any remaining indentation. Thanks to @rkern for suggesting the solution approach. Closes gh-1890.