Simulation queue

[jammyc]

Similar to (and extending) the batch mode but allowing different variants, projects and simulation configurations to be queued to later execution.

For example, if we have several batches to run (say, south facing, east-west and tracking for the same site, with and without storage), each taking a few hours, at present we can set one running but have to wait for completion before the next can be configured. If someone is not present this is of course dead time. If we could queue batches during the day to run unsupervised overnight it would be a substantial time-saver.

Alternatively, allowing multiple instances of PVsyst to run in parallel without creating file access clashes would at least mean we can start work on the next run while the first processes.