Fix typo
Refactor apn name getter
Get initial values from GConf
Implement service provider persistence through GConf
Fix reset provider and plan index when parent change
Redesign internal list of XML elements and transform on output

It transforms from XML element to a simplified custom object (Country,
Provider and PLan) at the lastest point possible, on get_* methods.

Internally, keep the elements on lists.
Adapt initial fetch procedure
Take into account countries without providers
pep8
Add tests that go through all options