Install docs
some more doc polishing
doc improvements
Merge pull request #129 from gladhorn/docs

Docs
Remove unused and buggy forward declarations.
Merge pull request #131 from nierob/smallFixups1

Remove unused and buggy forward declarations.
Remove out of date documentation
Remove unsafe and unsed global qml engine pointer
Merge pull request #132 from nierob/smallFixups1

Small fixups1
Merge pull request #128 from nierob/smallFixups

Use common delete_icon.png for todo and image gallery examples
Do not delete QNetworkReply directly in finished slot

The QNetworkReply can not be deleted in a slot directly because more
then one slots may be connected