Update to 1.1pre2, which adds the '-c command' switch to make
penv take lots of different, exciting actions:

[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -c mkdir
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -c set JADETEX=no
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -S A4=yes
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -L
JADETEX=no
A4=yes
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -c reset A4
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -R JADETEX
[roam@straylight:v0 /usr/ports/textproc/docproj]$ penv -L
[roam@straylight:v0 /usr/ports/textproc/docproj]$