extensions/main: LauncherPools now do not need the structure anymore.

The structure option is still available for users which want to tweak the order of the Pool.
Also now the configuration parser is embedded in every extension settings' object.
core/config: changed user config path to ~/.config/alan/alan.conf.
Added support for forced pipe menus.

Just prepend the extension you want to be piped with "Pipe:".
Keep in mind that if you want to pipe everything, just use alan-pipe.py.
The behaviour will be the same of the legacy alan, without caches of course.
0.90.0. You deserve it, alan.