Add the homepage back to the navigation

Fixes #236
Use os.path.sep for Windows support

Fixes #238
Replace another slash I missed.
Added a test for the path handling and found a bug
Merge pull request #276 from d0ugal/win-path

Use os.path.sep for Windows support
Raise a configuration error for invalid pages configs
Merge pull request #280 from tomchristie/invalid-pages-config

Raise a configuration error for invalid pages configs
Fixed URL parse error when using GitHub Enterprise

GitHub Enterprise deployments are a little unpredictable and this patch removes an error when using `mkdocs gh-deploy`.  It also includes a few PEP8 cleanups.
Merge pull request #284 from major/ghdeploy-github-enterprise-fix

Fixed URL parse error when using GitHub Enterprise
Check for CNAME file when using gh-deploy

If a CNAME file exists in the gh-pages branch, we should read it and use that URL as the expected GitHub pages location.  For branches without a CNAME file, we will try to determine the URL using the origin URL.
Merge pull request #285 from major/enable-ghdeploy-cname

Check for CNAME file when using gh-deploy
Merge pull request #271 from d0ugal/add-homepage-to-nav

Add the homepage back to the navigation
Fix test failure

Caused by a change breaking a new test that had been sitting in a PR.