#3 Add xslt1 support

[David Lee]

Current xlst command uses Saxon9. This is XSLT2.0. This is "generally compatible" with XSLT1.0 stylesheets but there are cases when a XSLT1 processor is desired.
Add an "xslt1" command which uses Saxon6 Jars to run the legacy saxon xslt1.0 compatible transformer.

[David Lee]

Discussing with Micheal Kay, he says that xslt1 stylesheets should work with xslt2 processors with no change unless they use enhancements/special-features so there is no point in supporting an xslt1 explicit command