Add better debugging/reporting tools

[GaretJax]

When helping other users, it is very useful to have some nice features such as:

• Dropping into pdb when an exception is raised
• Dropping into pdb when taskstatus.fail is called (one frame up)
• Logging errors via Sentry

At least pdb shall be activated with a -d/--debug flag, Sentry could be active all the time.
Could also be interesting to start logging things and provide a -v/--verbose flag.

[GaretJax]

-d was added in 0.6.0, but starts pdb only when an exception is raised.