highlight: only pygmentize for HTML mimetypes
For non-html mimetypes it doesn't make much sense. This also fixes the
issue that highlight unconditionally adds a <link/> tag for its CSS to
the template's header (which is pointless in text/plain output).
#!/bin/sh
cat >> $HGRCPATH <<EOF
[extensions]
alias=
[alias]
myinit = init
cleanstatus = status -c
unknown = bargle
ambiguous = s
recursive = recursive
EOF
echo '% basic'
hg myinit alias
echo '% unknown'
hg unknown
echo '% ambiguous'
hg ambiguous
echo '% recursive'
hg recursive
cd alias
echo foo > foo
hg ci -Amfoo
echo '% with opts'
hg cleanst