function tex2svg( str, options, clbk ) {
	if ( arguments.length === 2 ) {
		// Assume that `options` is a callback argument...
		return factory( {} )( str, options );
	}
	factory( options )( str, clbk );
}
Converts a TeX or LaTeX string to an SVG.

@param {string} str - string to convert
@param {Options} [options] - function options
@param {PositiveInteger} [options.width=100] - container width in `ex`
@param {PositiveInteger} [options.ex=6] - `ex` size in pixels
@param {boolean} [options.inline=false] - specifies whether to format the input string as an inline equation
@param {boolean} [options.linebreaks=true] - enable linebreaking
@param {Callback} clbk - callback to invoke once finished
@throws {TypeError} first argument must be a string
@throws {TypeError} options argument must be an object
@throws {TypeError} must provide valid options
@throws {TypeError} last argument must be a function
@returns {void}

@example
var eqn = '\\operatorname{erf}(x) = \\frac{2}{\\sqrt\\pi}\\int_0^x e^{-t^2}\\,\\mathrm dt.';

tex2svg( eqn, done );

function done( error, svg ) {
    if ( error ) {
        throw error;
    }
    console.log( svg );
}