ovs init initialises the certificate authority and ovs configuration. Previously these tasks were performed by special jobs for the package manager. Using a plain shell script is easier to test and uncouples the configuration of ovs from the package manager. The configuration steps were just writing text files from templates anyway.
These changes also include removing the openssl ASN1 workaround hacks.
There is still a lot of work to do to get ovs as a deb package without having to rely on the more advanced debian packaging features present in the files like debian/changelog, debian/compat, debian/templates etc. but this is a start!