pre-seeded providers should not be in user's config directory

currently, the app relies on config/leap/providers for storing the pre-seeded providers. when run from the package, the path is ~/.config/leap

this creates a number of problems:

(1) because ~/.config/leap will not exist for users running the packaged version, there are then no pre-seeded providers (2) if a user removes their configuration directory, they also destroy all pre-seeded providers

loading pre-seeded providers should probably be done via a search path, searched in this order:

(1) ~/.config/leap/providers (2) bitmask_app_directory/apps/leap/bitmask/provider/providers (3) /usr/share/pyshared/leap/bitmask/provider/providers

or where ever you think it best to put the pre-seeded providers that come with the app.

by using a search path, we can have pre-seeded providers, but then also more up to date json files and cert files in ~/.config that override the defaults.

(from redmine: created on 2013-12-11, closed on 2014-06-11)