Added actions on GUI to add and remove containers.
GetFileList() now returns all available information.
Added development authentication.

The credentials can be passed on to the application using
environment variables. This is only an intermediate step
used for developing and will be removed in future versions
once the connection list feature has been implemented.
Moved development authentication to 'Shown' event.
Added LoadingDialog to be displayed during long operations.
Replaced marquee progress bar with spinner animation.
Current task text can now be changed via property.
The number of entries will now be displayed in the status bar.
Entry count will now be formatted correctly according to locale
Containers can now be selected in the tree view.
Renamed GetFileList() to GetEntryList() for consistency.
Added mime type support for entry list.

This means, that each entry list will show an icon
representing the file typ (if detected successfully).
Loading form will now be shown.
User's attempts to close the loading dialog will be cancelled.
Censored password in ToString() method output.
Message log is now implemented.