Better gitignore rules

to avoid committing xcode user interface data, which are not relevant to
the project
Improve settings customization for subproject

because subprojects do not have to make changes on the source code to
defines their own settings
Add a `cardAutoresizingMask` property for potential customization
Add `cardEnablePressGesture` configuration option which fixes #9
Add `cardPanGestureScope` configuration option which fixes #10
Merge pull request #8 from dulaccc/enhance-configuration

Enhance configuration