rose metadata: fix env-val triggering
Add a value-hints widget for metadata Ticket 1322
Test battery: fix xxdiff dependency

Tests were requiring xxdiff to be installed. This fixes the problem, and
allows developers to configure their favourite `difftool` when running
the test battery. The default is to print a unified diff to STDERR.
Merge pull request #1457 from matthewrmshin/fix-t-xxdiff

Test battery: fix xxdiff dependency
Merge branch 'master' into 1322_metadata_value_hint
Bring html documentation for rose mpi-launch up to date.
Merge pull request #1459 from arjclark/update_cli_doc_mpi_launch

documentation: Update html documentation for rose mpi-launch
Update for release
Update CHANGES.md
Update CHANGES.md
rose metadata: values hints improved Ticket 1322
rosie create: configurable default access-list
Merge pull request #1460 from matthewrmshin/rosie-create-access-list-default

rosie create: configurable default access-list
Add MIRROR Jinja2 variable in rose-stem and associated test
Implement Matt's tidier suggestion
rose date: fix --calendar=365day|366day option

Option documented but not implemented correctly.
Merge pull request #1463 from matthewrmshin/rose-date-365-366

rose date: fix --calendar=365day|366day option
Merge pull request #1461 from scwhitehouse/mirror_var

Add MIRROR Jinja2 variable in rose-stem and associated test
Update CHANGES.md
Merge pull request #1458 from kaday/1322_metadata_value_hint

rose metadata: value hint