New MeshCAM Version

Just wanted to let everyone know that Beta 6 has been uploaded to
www.robgrz.com. The following is a list of changes. Most came
directly from user input, so I hope the changes will be useful to
everyone. A final release is getting closer so if you have a request
then get it in now.

- Updated 3d drawing code to not redraw the view if a dialog is dragged
across it.
- Updated ZMap rendering code. Tests show that large ZMaps redraw
about 20% faster.
- Added Bitmap and ZMap display quality settings under the
Edit->Preferences menu. These settings only affect the display, not
the toolpath.
- Changed Bitmap import dialog to allow the stepover to be specified
independently of the resolution and dimensions. This is done by
automatically resizing the bitmap prior to conversion to 3d.
- Fixed ASCII STL import error. It seems that Autodesk Inventor ends
an ASCII STL file with "endsolid" rather than "endsolid OBJECTNAME".
This caused the imports to fail.
- Found an obscure bug where a memory allocation could fail if too
large a Binary STL is loaded.
- Added GCode output configuration. Allows the user to specify block
numbering as well as allowing arbitrary code to be inserted before and
after the toolpath.
- Made the stock resizable for a bitmap based geometry.

Thanks to everyone for these suggestions and bug reports,
Robert