Config migration

[tewinget]

On install/update:

• Create a conf.d/ if it does not already exist.
• If an existing config file exists, move it to a .bak (or similarly renamed) file and inform the user.
• Create an example lokinet-example.ini in conf.d/ with commented defaults and a conspicuous comment at the beginning noting that it will be overridden on update/reinstall, and the user should use it as a template to create a separate config file rather than modifying it in-place.

[jagerman]

Undecided on whether we should push to target for this back to .11.