Federated the tests into individual files per function.  Also made the performance tests are now built-in loops to prevent extra time from re-running the whole script.  Also built a namespace file to still be able to test all the items in a namespace at once.
Updated the changelog script to be more properly aware of its own location.
The core_ToolExists function is ready for tests now.  Likely needs some debugging.  Need to add a list of requirements to SBT docs for coreutils and grep.  If perl isn't GNU licensed, should consider using ToolExists for all SBT functions using it.  I want to keep the external programs used in SBT as minimal as possible.