Long-running tasks

[joewandy]

1. For long running tasks, show a progress bar or some message telling users to wait
2. Would be good if we can submit tasks to run in the background, e.g. using celery?

[joewandy]

Two long running tasks are slow in particular and really need some kind of 'Please wait' message ...

• the initial mapping of data using reactome
• PLAGE analysis

[joewandy]

Added the message for the initial data submission. Not yet done for the others.