- Fixed message for XSLT variable check.

- Modified text of some messages. ...

- Modified XSLT processor check to key off XSLT environment variable.
- Made XSLT environment variable mandatory for the configure script.
- Added cut, date, expr, composite, ps2pdf.
- Moved position of shiftbbox.

- Changed text of messages.

- Streamlined error test. ...

- Revamped user output.

- Added base infrastructure for build system configure script.