Fulfillment of issues #12 and #13

Added HyperlinkUtility and MouseUtility to fulfill issues #13 and #12, respectively.

There is a third class added called ElementUtility which implements the
functions referenced in HyperlinkUtility, which I assume Logos has
somewhere not public, so I hope they don't use this public utility
library and it conflicts.  If so, I can move the functions elsewhere.