Re-root logfile paths

[nbastin]

Our log paths are really long, but they all share a common root that could easily be pruned, maybe something in the config file:

files-prune-root: '/mnt/log-data-store/'
files:
  - '/mnt/log-data-store/privoxy/varlogprivoxy/privoxy.log'

(That path is too wide for the popup, and doesn't make a lot of sense to the end user in any event)

[joaopsys]

I would also really appreciate this. Maybe an option to only show the filename and not the full path?