[connman-qt] Add SavedServiceModel

SavedServiceModel is a model exporting the list of favorite services
for a nominated technology.  Saved services are reported even if they
are not currently detectable.
Merge pull request #60 from lpotter/master

[connman-qt] enable passing of browser requests from connman
Merge pull request #58 from matthewvogt/saved-services

[connman-qt] Add SavedServiceModel
Update connman version dependency
[connman-qt] Allow model changes to be inhibited

Asynchronous changes are problematic if the UI depends on the model
indices to be stable during an operation.
Merge pull request #61 from matthewvogt/inhibit

[connman-qt] Allow model changes to be inhibited