[DRE-maint] Bug#589119: --scss important too

[Jason Woofenden]

The --scss commandline option is also missing from the man page.
This switch is needed to have sass parse the scss syntax from
stdin. (scss seems to be the recommended syntax now, since that's
what all the docs on the site use.)

I got most of the way through filing a bug that sass couldn't parse
properly from stdin before I discovered the --scss option somehow.

Take care,    - Jason