add a delete_syncstring method to the database
add a delete_syncstring method to the database

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