Fully customizable configuratoin

[nhochberger]

Create a configuration file that holds all information. E.g

• location for weather widget
• url of RSS-feed to be used with news module
• ...

[nhochberger]

This is more urgent than initially expected.

• Every custos module can define its own configuration
• Module configurations can be accessed via a central configuration dialog
• Store configuration in user's directory
• If no configuration file is found, create one with default values (migration!)
• Default values are to be worked out

[nhochberger]

Modules need to read the required fields from their configuration at the begin of their start()-methods.

[nhochberger]

Configuration entries are now applied automatically upon starting the application. In order to correctly apply the configuration entries, just implement/change the applyConfiguration() method of a module. If the configuration is changed by the user (later on), this method can be called in order to set the new values.

[nhochberger]

Configuration now works.

Mind #34