Make it possible to query any key value pair from device data section.

Signed-off-by: Marko Saukko <marko.saukko@jollamobile.com>
Merge pull request #4 from saukko/key-value

Make it possible to query any key value pair from device data section.
Rewrite settings from settings.d only if there are new changes; move board mappings to settings.d
Disable echo on rndssu password prompt
Only sync after complete files; use QDir filter for ./..
Replace QDir::NoDotAndDotDot with QDir::NoDot|QDir::NoDotDot for Qt5
Add linebreaks to rndssucli messages
Add basic variable resolver and unit tests
Start using new variable resolver; sync all writes to settings
Use the release() function for gettings release.

Signed-off-by: Marko Saukko <marko.saukko@jollamobile.com>
Add documentation for variable substitution in repos.ini
Limit recursion depth for variable lookup as failsave
Rename SSU CLI from rndssu to ssu
Report variant as well
Start using adaptation-repos stringlist for adaptations, allow freeform variables for adaptations
Return good repo url if adaptations don't exist -- duplicating repos is better than failing
Add support for := variable substitution
Allow parameter override in URL lookup
Export basic set of repositories for a device
Add some device mode logic to ssu core