APPID: check for NULL pointers and do basic checks.

Signed-off-by: bert <bert.timmerman@xs4all.nl>
Removed unwanted files from po/POTFILES.in.

Signed-off-by: bert <bert.timmerman@xs4all.nl>
3DFACE: added version R13 to Doxygen comments.

Signed-off-by: bert <bert.timmerman@xs4all.nl>
3DSOLID: added version R13 to Doxygen comments.

Signed-off-by: bert <bert.timmerman@xs4all.nl>
ACAD_PROXY_ENTITY: removed whitespace.

Signed-off-by: bert <bert.timmerman@xs4all.nl>
APPID: added version R12 to Doxygen comments.

Signed-off-by: bert <bert.timmerman@xs4all.nl>