t:rose-suite-clean: tests.

Test cleaning while the suite is stopped, interactive mode.
Test cleaning while the suite is running.
t:rose-suite-clean: fix typo.
Merge pull request #780 from matthewrmshin/t.rose-suite-clean

t: rose-suite-clean: test battery
Fixed incorrect html nesting.
rose.popen: print `return-code` instead of rc

Supersede metomi/rose#778, but use hyphen instead of space between
`return` and `code`. This should make it easier to parse.

Modify `rose test-battery` for the change.
Merge pull request #781 from arjclark/clock-tut-correct

tutorials: clock-triggered: Fixed incorrect html nesting.
Merge branch 'master' of github.com:metomi/rose into metomi-gh-pages
Merge pull request #782 from matthewrmshin/popen-return-code

rose.popen: print `return-code` instead of rc
Merge branch 'master' of github.com:metomi/rose into gh-pages
Merge branch 'gh-pages' of github.com:metomi/rose into gh-pages