Work with chained offsets.
Add tests.
Merge remote branch 'upstream/master' into chain_offsets
Review feedback.
Improved the graph_suite function for tests.
Sort compared files in one test.
Merge remote branch 'upstream/master' into chain_offsets
Feedback implemented.
Merge pull request #1097 from hjoliver/tests-graph-comp-fix

Improved the graph_suite function for tests.
Merge pull request #1084 from arjclark/chain_offsets

#1048: Enable chaining durations