Checks for hasOwnProperty in function render

When render() is called on an object with prototype functions,
prettyjson prints them. This is almost always never the desired
result. This patch fixes this behavior.
Adds hasOwnProperty check in getMaxIndexLength (util.js)

This adds the hasOwnProperty check in getMaxIndexLength. Without this,
there may be an odd offset when there is something in the prototype.
Add tests for PR #4
Include jscoverage dependency using npm
Bump version to 0.9.0