Proper WSL support

[ghost]

Right now, setting up keyring on WSL is complicated and some steps need to be done every time before a script using keyring can be launched:
#566

It would be great if at least the steps that need to be done every time when running a keyring based script could be somehow encapsulated in keyring itself.

[jaraco]

I'm not confident there's anything this library can do short of more visibly documenting the findings in that other issue, but I welcome contributions that will help.