Added cImage class

This class is able to hold a single glyph and
a whole character map image. It is mainly for
storing the raw byte data for internal use. The
user of this library will probably never get in
touch with this class. Yet it is an exposed type
in case the user wants to do something special
with it.
Changed cImage to 2 channels only

The ftxx::cImage is not a general replacement
for abstract images. It is a very specific type
of image that gets used in the font library. For
this purpose we only need 2 channels and nothing
else. If the user needs more then he should use
other image classes and write converters for
cImage to whatever data format he wishes to use.
CreateFont image testings

CreateFont now creates glyph images and puts
them in a ftxx::cImage object.