Log Message:
update to pcb-20060422.  This release represents a fairly major overhaul
of PCB.  In particular, the core code has been isolated from the GUI code
and there are now both GTK and Motif/Lesstif GUI's available.  In addition,
command line exporting to RS-274-X, postscript, encapsulated postscript and
png are directly supported.

In addition, there have been many bug fixes since the last packaged snapshot
release.