Moved Opacity logic from ImageComponent to GuiComponent so any extender
of GuiComponent che implement its opacity logic.
Implemented Opacity logic for TextComponent (now text can have fade
animation)
Folders should now be sorted alphabetically.
Will now fall back to a system font if LinLibertine.ttf is not found.
Added a Menu button.
Began working on a simple menu.
Scrolling will now occur if the input is held (not just keyboards anymore!).
Initial XML gamelist support. If a file named gamelist.xml is present in the directory ES is run from, it will be parsed and the detailed GuiGameList will be used. Games are matched by absolute path, and a name, description, and image path can be read.
PugiXML is used for parsing XML files - its license can be found in src/pugiXML/pugiXML_license.txt.
SDL_image is used for loading screenshots with the detailed GuiGameList.
Almost all invalid bash characters should be escaped in ROM paths now - including !$^&*()[]<>?;'"\.
