The use of printf, wxLogDebug, and std::err/std::out causes excessive
debugging output which makes finding specific debugging messages more
difficult than it needs to be.
There is still some debugging output in test code that really needs to
be moved into a unit test.
Add debugging output section to the coding policy regarding debugging
output.
This only tests the InterceptsPositiveX() and InterceptsNegativeX() used
for finding the midpoint of an arc.
Tidy up some of the trigo.h header Doxygen comments.
Wayne Stambaugh
Tomasz Wlostowski
Seth Hillbrand
Ian McInerney