Some usability improvements and bug fixes

The latest release 'AleHu 20140531.zip' fixes a couple of bugs that incorrectly forced the client to use the (default) AleHu Testserver instead of the server specified at registration.

Besides, usability was improved a bit by memorizing things such as window size and position. So the next time you start up the client again, it appears at the same location where you quit, having the same size as with the previous session.

Furthermore, the client now memorizes the directory where you last time selected an attachment. So in case you transmit a lot of files residing in the same location on your harddrive, this should facilitate the selection of your attachments. Same is true for the directories used for exporting and importing users.

Since the native Java GUI 'look and feel' has the air of beeing a bit old fashioned and boring, the header are was pepped up by using a metallic background. It's not really much but it makes the client a bit fancier :)

Last but not least, finally the settings submenu of the Help menu was implemented. There, you can find a couple of read-only settings specifying the AleHu server your client is connected to and you can adap the heartbeat period as well as the proxy settings.