Database.Open (and overloads) shall throw an IncompatibleDatabaseException when applicable

[Kittyfisto]

Especially during the initial development phase, it's very likely that breaking changes will have to be introduced to the database schema. IsabelDb should detect this and throw an appropriately named exception in such cases (such as IncompatibleDatabaseException). In order to improve feedback, the database itself should both store the version of IsabelDb which was used to initially created the database, as well as an every increasing database version (starting at 1, increment whenever a breaking change is introduced).

[Kittyfisto]

Done