----------------------------------------------------------------------
--- 2011-10-30 Release 7.20.4 ---
----------------------------------------------------------------------
* added lighting model visualization options for archer - Bob Parker
* reid command now takes optional -n "incr by" value - Erik Greenwald
* reid command now returns the last region ID set - Erik Greenwald
* improved nirt support for non-UNIX-style text files - Sean Morrison
* added new relos thickness reassignment command to mged - Carl Moore
* support for loading archer plugins with spaces in name - Bob Parker
* added 'exists' object detection command to mged/archer - Cliff Yapp
* added archer BoT split/flip/sync surface cleanup panel - Bob Parker
* added new g-dot exporter for hierarchy visualization - Sean Morrison
* improved g-vrml successful exporting and reporting - Richard Weiss
* added -b BoT dump and -e evaluation option to g-vrml - Richard Weiss
* improved obj-g polygonal import - Nicholas Reed, Richard Weiss
* fixed mged crash after killing an illuminated object - Abhijit Nandy
* tightened default polygonal mesh export tolerance - Sean Morrison
* converted introductory Tcl/Tk presentation to Docbook - Tom Browder
* initial support in archer for editing pipe primitives - Bob Parker
* fixed NURBS raytracing crash due to invalid geometry - Sean Morrison
* fixed memory leak when saving BoT geometry - Nicholas Reed
* improved mged object name globbing support - Sean Morrison
* improved bounding box for rpc, epa, ehy, hyp primitives - Cliff Yapp
* improved handling of degenerate face facetization - Richard Weiss
* add support for .png file output in rtwizard - Cliff Yapp
* improved rtwizard's invocation of rt - Cliff Yapp
* added object path and keep options to conversion.sh - Tom Browder
* 'keep' command includes sketch when keeping revolve - Sean Morrison
* fixed mged 'mater' command inheritance setting bug - Richard Weiss
* fixed mged crash removing comb members during edit - Richard Weiss
* modified archer startup to not require html documentation files
- Cliff Yapp, Brandon Hinesley
* improved mged/archer/bwish run-time path behavior on Windows
- Cliff Yapp, Bob Parker
* upgraded libpng to version 1.5.4 - Cliff Yapp
* improved performance of step-g importer - Zach Easterbrook
* fixed browsing mged html help pages on Windows - Bob Parker
* restored mged 'rt' command output to console window - Sean Morrison
* fixed infinite loop bug plotting NURBS wireframes - Sean Morrison
* added new 'ringworld' procedural geometry generator - Erik Greenwald
* fixed mged Manual page item in help menu - Brandon Hinesley
