syncstring: added MAX_LENGTH cap on size of syncstring.
syncstring: added MAX_LENGTH cap on size of syncstring.

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