Example improvements and docs
More todo example

The credit goes to Jens for picking Colors and Delegate look and feel.
Major doc improvements

Get the Qt Quick version of the docs
to work and add documentation for much of model
and reply classes.
Welcome C++ TODO example.
Fix a comment in Image Gallery example
Rename widgets examples to qt examples

It is just temporary to reduce amount of changes on the server side.
Merge pull request #143 from nierob/example

Examples
Merge pull request #145 from gladhorn/docs

Docs
Use fake reply in EnginioModel::remove and EnginioModel::setProperty.

It unifies behavior between EnginioModel and EnginioClient
Add more QVERIFY in EnginioClient tests
Do not return null EnginioReply in EnginioModel::setProperty.

Create a proper reply when an user try to update unknown role.
Make test check only one thing

EnginioModel is allowed to make additional requests so the test should
query only requests that were created by it.
Move re-parenting of a QNetworkReply instance to the EnginioReply ctor.

EnginioReply should take ownership of QNetworkReply, so there is no need
for manual re-parenting.
Add a tutorials page to docs
Merge pull request #146 from nierob/smallFixes

Small fixes
Remove imvalid TODO comment
Merge pull request #147 from gladhorn/docs

Add a tutorials page to docs
Unify a bit look of qml and widget version of TODO examples
Merge pull request #149 from nierob/example

Unify a bit look of qml and widget version of TODO examples
Document the image gallery qml example.