Add an open button in the container toolbar.
Fix medViewContainer::setDefaultWidget add a userClosable property to the contianers.
create a menue in the medViewContainer to embed open and split buttons.
Get icon visible in menu, use a simple QPushButton to maximized views, disable the close button when the view is maximised.
Save and restore geometry of the QFileDialog to open a file from the system.
Remove useless svg file, change margin of the container's toolbar.
Put the maximised button int the toolbar's tool menu.
commit after rebase
Merge pull request #161 from rdebroiz/open_button

Add an open button in the toolBar of the medViewContainer