PR: Split Working Directory module

[rlaverde]

This is the last one 😄 (only missing the ones out of the spyder package) 🙈

workingdirectory
├── confpage.py
├── __init__.py
├── plugin.py
└── tests
    ├── __init__.py
    └── test_workingdirectory.py

[pep8speaks]

Hello @rlaverde! Thanks for submitting the PR.

• In the file spyder/plugins/workingdirectory/confpage.py, following are the PEP8 issues :

Line 27:21: E128 continuation line under-indented for visual indent
Line 28:21: E128 continuation line under-indented for visual indent