Updating widgets to be compatible with the new buffer modified system.
Merge pull request #10 from mholden8/ModifiedFix

Updating widgets to be compatible with the new buffer modified system.
Fixes #9: Choose the analysis range directly based on the timestamps, rather than indirectly using the spin box values.
Fixing various memory leaks.
Fixes #11: MarkEnd button successfully changes analysis end time.
Merge branch 'master' of https://github.com/mholden8/PerkEvaluator
Only send current transform and time - metrics are responsible for storing previous values.