[dftimewolf] Removed convoluted imports, make config a class

[dftimewolf] Removed convoluted imports, make config a class.

- Removed dynamic imports feature
- internals.py - Configuration is now globally stored in a class with setters and getters
- user_config.py.sample - this is where the user configuration goes; loaded modules, recipes, specific configuration tweaks.
- local_plaso.py - recipes are now classes since they can absorb global configuration settings when loaded

The UX is a bit less straightforward but it simplifies the codebase a lot.

[tomchop1, 2017-08-07 11:29:38]

Code updated.

[onager, 2017-08-07 12:58:46]

On 2017/08/07 11:29:38, tomchop1 wrote:
> Code updated.

Tests still don't work, as timewolf_recipes is required before the setup code
runs.

[onager, 2017-08-07 13:00:10]

https://codereview.appspot.com/328180043/diff/20001/dftimewolf/internals.py
File dftimewolf/internals.py (right):

https://codereview.appspot.com/328180043/diff/20001/dftimewolf/internals.py#n...
dftimewolf/internals.py:6: class Config(object):
Rename file to config, if that's all that's in this file.

[tomchop1, 2017-08-14 15:40:35]

Code updated.

[onager, 2017-08-23 09:25:59]

LGTM