rose.stem: fix import.

Broken by #741, and tidy up a left over unused method in `rose.run`.
Merge pull request #744 from matthewrmshin/fix.741

rose.stem: fix import.
rose.stem: fix `rose` global name.

N.B. `rose` was implicitly imported by `import rose.run` before #741.
Merge pull request #745 from matthewrmshin/fix.rose-stem.import

rose.stem: fix `rose` global name.
rose.suite_run: fix bad variable name.

Bug introduced in #741 by a rename.
Merge pull request #746 from matthewrmshin/fix.rose.suite_run

rose.suite_run: fix bad variable name.
Merge branch 'master' of github.com:metomi/rose into gh-pages