CODECS with Temporary files using tempfile.mkdtemp() enabling multiple processing.

[kny5]

For the issue of multiple processes overwriting temporary codec files at /tmp/. Placing temporary codec files like: "temp_dxf.dxf" inside a directory created using tempfile.mkdtemp(). Ensuring, no io file bottlenecks, racing conditions or unwanted overwriting happens while using tools like, cadorchestrator server and nimble, or any other bulk multiple processing.

A class temp_dir was created with the methods:

init for initialisation and creation of the directory, and dlt for safely removing the path and directory if needed.

[jmwright]

Thanks @kny5 ! The FreeCAD failure is not your doing. It's failing in another current PR too. It does look like there is a lint issue though.

[jmwright]

@kny5 If you merge master into your branch it should fix the FreeCAD test.

[jmwright]

Closes #39