Refactored Button to use signals/slots rather than a handleEvent method.
Implemented Slot::disconnectAll().
Implemented Widget::disconnectAllSignals().
RadioToggleButton now uses signals/slots.
Added visibility state to Widget.
Now only visible widgets handle events.
Created basic window class with basic functionality.
Implemented Window::isVisible().
Implemented Window::draw().
Deploywindow is now a Window but it still hase some bugs concerning sprite of radio toggle buttons.
Merge remote-tracking branch 'origin/gui-widget' into gui-improvment
Merge remote-tracking branch 'origin/signal-refactoring' into gui-improvment

Conflicts:
	include/gui/widget.hpp
	src/gui/widget.cpp
Merge remote-tracking branch 'origin/gui-window' into gui-improvment
Merged src/gui/widget.cpp which i forgot to merge in commit 6113617. (stupid me *slap*)
Widgets now hold their own size which must be set by constructor.
Made BoardRenderer a widget that is now called BoardWidget.
BoardWidget now calculates spritedimensions and singlespritescale when setting the board and saves it as attributes.
Changed visibility of Widget::window to protected.
BoardWidget now can now move the Cursor.
Added some documentation for Widget::mouseFocus attribute.