Migration to Jedi 0.17.1, first part (does not take advantage of jedi rename)

[edelvalle]

This improves autocompletion for Django. Also improves autocompletion speed, has the concept of project.

Future PR will be Use the jedi rename utility instead of our own: https://jedi.readthedocs.io/en/latest/docs/api.html#jedi.Script.rename Maybe implement search anything, since jedi also now provides that: https://jedi.readthedocs.io/en/latest/docs/api.html#jedi.Project.search

there are also some interesting refactoring tools: https://jedi.readthedocs.io/en/latest/docs/api.html#jedi.Script.extract_variable and bellow...

[edelvalle]

Is complicated to do that split, because the library changed APIs and deprecated quite some stuff.