webapp: handle objects occuring as unhandledrejection reasons
webapp: handle objects occuring as unhandledrejection reasons

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