completed addition of \section, \subsection and \par to drawing.dox

consistent \section, \subsection, \par applied to complete file.
corresponding source code comments for functions still to be completed.



git-svn-id: file:///fltk/svn/fltk/branches/branch-1.3@6399 ea41ed52-d2ee-0310-a9c1-e6b18d33e121