Generalized Suffix Tree (updated)

Restricted external access to many construction specific variables, so
they don't accidently get changed when working with the generalized
suffix tree.  Added @property getters for the variables that need to be
accessed externally.  Changed a couple function names to more precisely
define their purpose.  Slightly modified a few routines.  Overall
functionality remains the same.
Suffix Tree Construction Problem (syntax update)

Updated syntax to match the updated generalized suffix tree syntax.
Longest Shared Repeat Problem (syntax update)

Updated syntax to match the updated generalized suffix tree syntax.
Shortest Non-Shared Substring Problem (syntax update)

Updated syntax to match the updated generalized suffix tree syntax.