Draft: Oracle database support
This MR introduces Oracle database as one of the supported JDBC target, by embedding the Oracle drivers & utilities directly in the project.
The migration schema is nicely generated by the JPA Buddy plugin under IntelliJ IDEA, but there is some little quirks about Oracle, mainly on the column names (blame the parser) so I have to modify it a little bit.
In fact, the rest worked quite fine where I tried a live game using Splash Plus, and so far so good. There are some other features I forgot to separate and I need to cherrypick them in another branch as another MR. So before that this would a draft.
In theory, this could work out the same for Postgres, or really any database supported by Hibernate and JDBC (so unfortunately no luck for you MongoDB fanboys out in the wild) by repeating the same procedure, but it should just work out of the box without that "workaround" I suggested.