Better progress tracking, dropping studies and multiple versions of Ensembl annotation supported

Version 2.0 of the EVA pipeline has changed the workflow manager technology. Instead of tracking progress of steps as a whole (done / not done), it now split the work in chunks of configurable size. This way, if a step has processed millions of variants before failing, it will be resumed from that point instead of completely restarted.

This version replicates the functionality present in the previous version and adds the following:

• Better job parameters management, report of user errors, etc.
• New job for dropping studies
• Multiple versions of functional annotation generated using Ensembl Variant Effect Predictor
• Better detection of when the Ensembl VEP process hangs or fails
• Displaying estimated progress percentage for several steps

Please note the database schema has changed to support multiple versions of the annotation and the migration tool can be found in a module of the repository eva-tools.