ghostscript commits (fix of back out request)

[Alexander Kabaev]

Hello,

your recent commits to ghostscript port have broken them for
users which legitimately use GS_OPTIONS environment variable 
to pass default options to the gs binary. script/configure
scripts in ports abuse this variable for something absolutely
unrelated, i.e. the list of drivers to compile with the port.

Could you please either back your changes out or fix them?

--
Alexander Kabaev