some fixes so building works on Linux.
some fixes so building works on Linux.

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