add missing semicolons

Its better to keep consistent style and being explicit rather than
relying on JavaScript to get it right.

	modified:   src/dotplot2.js
Change variable name to not mask input parameter

The variable name size masked the size parameter passed to the
function. This could cause unexpected results.

	modified:   src/dotplot2.js
Remove dupliate declaration of variables

JavaScript doesn't have block scope and removing multiple declarations
clarifies that the variable is accessible through the function.