* Rename all member variables and methods that reference the cross hair
code in draw panel object from cursor to cross hair to eliminate confusion
between the two concepts.
* Rename cursor capture call backs in draw panel object to improve code
readability.
* Create helper class for turning off the cross hair while drawing.
* Remove redundant block clear code.
* Remove redundant mouse capture call back reset code when end capture
call back is called.
* Remove unused function definitions in base draw frame object.
* Lots of minor coding policy and doxygen comment fixes.
Wayne Stambaugh
jean-pierre charras