You do not need res2h to build ES, only if you wish to modify resource
files.
Added a simple corner.png and bar.png for a border in the settings menu.
Added ImageComponent::setColorShift(unsigned int color) to change the
OpenGL color array.
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)
The ResourceManager provides a unified interface for accessing resource
data, embedded or from the filesystem, with
initialization/deinitialization handled automatically behind the scenes.
It also keeps from creating duplicate resources (e.g. when two
ImageComponents use the same image file).
Audio still needs to be moved over to it.
