Lot of manifests are using github tags to find the latest version the
url's and regex is mostly the same.
`checkver` now can also be the string "github" if the `homepage` links
to the github repo
If `homepage` is not the repo `{"checkver": "github":
"https://github.com/user/repo"}` can be used
* makes changes to almost all main repo files to be in accordance with .editorconfig
* some files in "test\fixtures\..." were left alone to avoid breaking tests
* NOTE: whitespace changes *only* (`git diff -b` shows no changes)