Partly implemented new databas opening UI code - work in progress

- It is now possible to create new keepass databases easily with a separate "Create new Database" page
- There is also an \Open Database" page which can be used to open any keepass database on the phone/SD-card/Android-Storage
- If the user does not have yet created any databases or opened any databases he will be presented with a default path "Jolla Documents: ownkeepass/notes.kdb" on the create database page (not yet finished)
- On the main page there is now a "Recent Databases" list which contains recently opened keepass databases, this is for easy access to common used database files (this is also partly implemented, meaning it will currently not being saved to settings and disappear if app is restarted)
- Database location combobox and textfield moved to Query Password Dialog
- When creating or opening a database the user can specify to open this database automatically on app start (button to page added but not yet functional)