+ About Widget naming conventions and placement on the source tree

Widgets should be named on the following naming convention:

		 TK_DescriptiveName

where TK stands for an abbreviature that identifies the toolkit used to
implement the widget. "Descriptive Name" is just that. A name that anybody
could remember easily and expressive enough to give an idea to newcomers
about what the widget does. Some examples could be:

		   Fl_2DLogFunctionDisplay.hxx 
		   Qt_2DLogFunctionDisplay.hxx
		   Mfc_2DLogFunctionDisplay.hxx
		   Wx_2DLogFunctionDisplay.hxx
		   ...

Note that the first letter of the acronym should be upper case, while the
other ones lower case.

Widgets, when added to the repository should be placed according to their
toolkit, to ease binary generation processes. More concretely:

		   src/Visualization/Widget/FLTK  ( FLTK based widgets home )
		   src/Visualization/Widget/Qt    ( Qt   based widgets home )
		   src/Visualization/Widget/MFC   ( MFC  based widgets home )
		   ...

if there does not exist a suitable directory for placing widgets for toolkit
X, feel free to create a new entry placed on src/Visualization/Widget using
as the folder name, the toolkit "official" acronym.