Allow injecting Paths not Files.

Make the ActionAliasMigrator use a Path, and add a basic
unit test. Need to make ConfigFile use paths to do anything
sensible.

Also refresh gradle libs in idea so JimFs shows up.

Change-Id: I0cb2692083d0fe117b91edce63d8417ddd74e288
Reviewed-on: http://gerrit.dmdirc.com/3999
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>
Add migrator for action-based performs.

This converts performs in the "performs" group into auto commands.
It doesn't touch any custom written global actions - will handle
those in a separate migrator.

Change-Id: I7226dfee1b705a9e057094f425703a1b051685df
Reviewed-on: http://gerrit.dmdirc.com/3998
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>