Star2html: htlatex version now supports input commands.

If it detects a \input command it will copy the file into the
working directory and update the \input command with the
correct path. Also stopped copying some latex2html icons
into the output directory.
Star2HTML: now support using environ var STARLATEXSUPPORT.

This is set to the path of the applications/latexsupport directory.
This will then set up TEXINPUTS, TEX4HTENV and TEX4HTHTF.
Note that for pdf builds you still need to have manually set the
TEXINPUTS path to contain $STARLATEXSUPPORT.
star2HTML: minor tidying