Merge pull request #81 from blackwarthog/master

Fix warning in filecontainerzip.cpp
MainWindow class
Add main window into App. Remove recent_window_size functionality.
Finally remove recent_window_size functionality
Fix bugs in MainWindow
Make tab from CanvasView window (Intermediate version)
Activate controls
Fixed CanvasView layout
Munu bar
Fix for Windows
Fix bug with disabled menu items
Make menu items "new" and "open
"Close" button
Scroll tabs
Fix warning
MainWindow: use Gtk memory management for widgets
New dock interface. (Not finished yet)
Allow to attach docks to main window
Moving menu from toolbox into mainwindow: declare menu items
Implement new menu items