Feature suggestion: Symmetric passing patterns in siteswap generator

[jkboyce]

An important subclass of passing patterns are those which are symmetric, meaning that each juggler does the same sequence of throws. (These throw sequences need not be all synchronized in time with respect to one another; when they are not then a symmetric pattern is called "staggered".)

The feature suggestion would be to add an option to the siteswap generator to find symmetric patterns, both staggered and not.