Added toString() to help with debugging.
Changed getAvailableTBs() to takes in whether to check if it can fit the
sum of activities duration and/or the edges in the minimum spanning
tree. 
Consequently, overload with methods that con't take in the new vars and
call with false to the boolean value
Checks if this TB can fit the AST (including sum activities and bridges
duration) in addition to legal times
Cluster manager working version, tested
Correct output printout