* Removed redundant 'int chans' parameter from the
'RDRenderer::renderTo*()' methods in 'lib/rdrenderer.cpp' and
'lib/rdrenderer.h'.
* Fixed a bug in 'lib/rdrenderer.cpp' and 'lib/rdrenerer.h' that
caused logs rendered to cart/cut in stereo regardless of the number
of channels specified.
* Added support for cart/cut rendering to the 'Render Log' dialog
in rdlogedit(1).
* Added a length check when rendering to cart/cut in
'lib/rdrenderer.cpp'.