resolves #4

~requested 300

These changes have already been merged somehow without the pull request so I'm doing this again.

Also these issues that have not been added yet.

I'm not sure if this next one will work since the build.xml isn't only for my program.
(15 points) Change build.xml so that it takes command line arguments -Dargs. If -Dargs isn't specified then make a target that prompts user for arguments before continuing. 

(10) Add SVSymbol class. (Similar to SVDefinition).

	(75) After SVSymbol issue is resolved. Instead of adjusting the dimensions of the triangle with the viewBox attribute for the main svg tag, save it as a symbol and set the viewBox of that instead. This will allow one to further manipulate the triangle (add more content, shear, scale, etc.), and prevent setting the viewBox of the entire svg document.

(50 points) Refactor / organize / improve documentation for SierpinskiTriangleBuilder class.