#5 Add text-only option to sis-installer.pl

[Renier Morales]

Add a --text-only option to sis-installer.pl. This is
useful when you don't want to install any graphical
packages on the system. --test-only would exclude the
SIS x11 package from being installed. Otherwise, the
user is forced to edit files to make the install work
on a non-graphical system.