Removed extraneous comma

IE7 doesn't deal well with extra commas at the end of javascript object
initializers.
Declare "pos" as local variable

This variable is set in the `for` loop on the next line. We should
declare it locally to avoid setting a global variable.
Removed unused variable
removed trailing comma which caused errors in IE7
Merge pull request #125 from rwhitmire/master

trailing comma was causing a bug in IE7
Merge pull request #118 from j2jensen/master

A few minor fixes
Properly closed mask object definition to prevent JavaScript error in IE7

Unclosed object generates a JavaScript error in IE7: "Expected identifier, string, or number"
Merge pull request #169 from holtkamp/master

Properly closed mask object definition to prevent JavaScript error in IE7