Finalize isar comparison

[yringler]

Isar went stable new years, so would be really cool to get a full isar benchmark comparison here also.

[yringler]

Related to #2

[greenrobot-team]

Thanks for the heads-up!

[greenrobot-team]

Finally had the time to update to the latest stable isar release 2.5.0. No longer need to manually edit the generated code!

There are still some TODOs though (using null IDs to auto-assign IDs, adding complex queries).