sagews: make it so in a worksheet __file__ is the name of the current worksheet.
sagews: make it so in a worksheet __file__ is the name of the current worksheet.

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