Perspectives, Pers_client_policy, Pers_about - Fix debug printing calls
Perspectives - Fix text display for weakly seen results

The tooltip was not getting set, causing the UI to show 'null'.
Makefile - Add target for installing plugin after build

Running 'make test install-fx' is must faster than opening the file by hand
Unit tests - Add tests for key_weakly_seen_by_quorum()
Pers_client_policy - Add tests for invalid check lengths for weakly seen keys
Unit tests - Add function to print a visual spacer

This just helps to visually group related tests
Unit tests - Add tests for certificates with short durations
Unit tests - Add tests for observations with gaps
Unit tests - Refactor quorum tests to add observations that don't end at the current time
Unit tests - Add more duration tests

- Add tests to check quorum calculation without gaps
- Add tests to check that results are the same with and without gaps
- Add third test case: gaps between two observations of the same key,
both within range
- Add a missing semicolon
Unit tests - Add tests to compare 'weakly seen' with and without gaps
CHANGELOG - Add notes for 4.3.7
Unit Tests - Add reminder to test localizations
Documentation - Copyedit notes on how to release new versions
Perspectives - Increment version for 4.3.7 release!