Resuming a session may result in different run_list

[Zygmunt Krynicki]

In the following example, resuming a session will result in a different run_list. This may be abused to inject jobs into a session and thus break the suspend / resume guarantee.

Assuming the following session:
- desired_job_list: [a]
- run_list: [a]
- results: []

Currently job a has no dependencies, let's say it has checkum a_checksum_1. It's checksum is not mentioned in the session file as it does not have any results yet. The session is saved with format 4

Let's modify the job database and inject a dependency a_dep on a.

Resuming the previously saved session results in the following data:
- desired_job_list: [a]
- run_list: [a_dep, a]
- results: []

I think we should have detected the modification and prevented this resume operation. This would not have happened in the 3rd format.