At the moment these are no different than strings, but they allow us to
do things like add URI handlers to file names if no scheme is provided,
and eventually do file existence testing. This also allows the web URI
to allow uploads as a means of passing a file in.
The configuration will only store the filename, because otherwise
someone could add a huge file which would need to be carried around in
the config forever after. Handling file existence errors is up to the
UI after the volatility library returns a "file not found" type
exception.
These are required by the Automagic interface, and so to prevent
importing from outside the interfaces namespace, these two classes
were moved into interfaces.
Note: also remove interfaces_configuration where ever possible
(this is not possible in the interfaces directory itself
because it would cause an import loop).
So this is where I ripped out the guts of the dependency tree
and made it a little better defined in some ways, and delayed
populating it in others. The validate function signature has
changed and I'm still up in the air whether to validate with
True/False or throw/catch exceptions.
So now, configurables have a list of requirements, these are
then bundled into a single requirement and can be passed to
automagic. Automagic runs a set of things over the deptree
to help build/manage it. These run in order of priority.
The tree is still built from the top down, but now automagic
can build branch from the bottom up and try and splice them
into the tree where appropriate. Hopefully this will make it
easier to see follow.