[errai-dev] Mosaic migration, part 1

I finished and committed the part of the workspace migration to mosaic layout managers. Bare with me if you see some things looking different or not even working as they used before: It's still work in progress and tried my best to retain most of the features, but some things still require additional work: - Leveraging UIBinder: I had to drop most of the UIBinder examples, because mosaic isn't there yet. The mosaic UI binder adoption is work in progress and as long as major bit's and pieces are missing on that side, we need to postpone using it. IMO we do a 100% adoption of declarative UI, when it's available instead of heaving a demo that partly works with that concepts, but still has to rely on programmatic UI assembly for most cases. - WSGrid: The nifty auto scroll feature has been disabled, because I couldn't make it work within the mosaic layout managers. It just blew up all of the time. But I think most of the other features made it into the new version. I was forced to rewrite many parts of the widgets and replace bit's and pieces with mosaic constructs. - CSS: The workspace and widgets CSS files have been dropped to a large degree, because they did party overwrite GWT base css properties which caused a lot of trouble in conjunction with mosaic. So bare with me, if it doesn't look exactly like it used to be. I did focus on functionality this time: This will be revisited on a larger scale, when we begin work the overall look and feel That's it for now, Stay tuned there is more to come. Regards, Heiko