sagews: make it so can't edit an input or output line.
sagews: make it so can't edit an input or output line.

DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,sagemathinc/smc,DrXyzzy/smc,DrXyzzy/smc,sagemathinc/smc,tscholl2/smc