Fix mapBool to return the default if we fall into the atoi() case but the string does not start with a digit.
Fix mapBool to return the default if we fall into the atoi() case but the
string does not start with a digit.

ellson/graphviz,jho1965us/graphviz,tkelman/graphviz,tkelman/graphviz,jho1965us/graphviz,jho1965us/graphviz,MjAbuz/graphviz,jho1965us/graphviz,ellson/graphviz,tkelman/graphviz,ellson/graphviz,kbrock/graphviz,MjAbuz/graphviz,kbrock/graphviz,MjAbuz/graphviz,kbrock/graphviz,MjAbuz/graphviz,jho1965us/graphviz,MjAbuz/graphviz,kbrock/graphviz,pixelglow/graphviz,tkelman/graphviz,ellson/graphviz,kbrock/graphviz,MjAbuz/graphviz,ellson/graphviz,BMJHayward/graphviz,jho1965us/graphviz,MjAbuz/graphviz,ellson/graphviz,BMJHayward/graphviz,ellson/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,BMJHayward/graphviz,jho1965us/graphviz,jho1965us/graphviz,MjAbuz/graphviz,BMJHayward/graphviz,pixelglow/graphviz,tkelman/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,jho1965us/graphviz,MjAbuz/graphviz,tkelman/graphviz,ellson/graphviz,tkelman/graphviz,ellson/graphviz,pixelglow/graphviz,pixelglow/graphviz,kbrock/graphviz,kbrock/graphviz,ellson/graphviz,pixelglow/graphviz,BMJHayward/graphviz,pixelglow/graphviz,BMJHayward/graphviz,MjAbuz/graphviz,kbrock/graphviz,tkelman/graphviz,tkelman/graphviz,BMJHayward/graphviz,pixelglow/graphviz,jho1965us/graphviz,pixelglow/graphviz,pixelglow/graphviz,kbrock/graphviz,BMJHayward/graphviz,ellson/graphviz,pixelglow/graphviz,tkelman/graphviz,kbrock/graphviz,tkelman/graphviz,kbrock/graphviz,pixelglow/graphviz,jho1965us/graphviz