Moving the handling of progress to GuiProgressBar

Adds an interface providing data for GuiProgressBar
Changed all containers simulating progress to implement the interface
Might contain some code formatting

Currently the Tooltip text is still set by the corresponding Gui class as there is no common pattern matching every variation currently used.
Compared to the previous implementation it is at least using a common interface and not some random public field.
The history does not indicate any changes to the formatting and I know for sure, that there a still files not correctly formatted (invoking a "Source > Format" in eclipse will produce a large number of changed files)