Add append, remove, setData and setValue to EnginioModel
and fix the initialization issue of EnginioClient.

Later we need to improve the abstraction for EnginioModel
and EnginioClient, this is just to make the examples work
by bringing the model to feature parity with the prototype.
Merge pull request #8 from gladhorn/dev

Add backend config file to gitignore
Fix warning
Fix crash when getting EnginioReply
Clean up headers

Usually Q_PROPERTY comes as first thing in the header.
Remove extra semicolon
Change order of parameters for setValue

In listmodel and other places the role comes first,
then the value, see for example:
http://qt-project.org/doc/qt-5.0/qtqml/qml-qtquick2-listmodel.html