This PR fixes the UI relative path issues mentioned in #73
Committed changes:
the fix makes use of the home_url() function to compute the absolute path we should save in the database for backward compatibility, so users don't need to add the path prefix for multisites anymore in the UI
added Follow link in backend for easier testing
fixed the redirection target URL, so when a relative path is provided, the home_url() is prefixed to it, added unit test as well
This PR fixes the UI relative path issues mentioned in #73
Committed changes: