rose suite-run/clean: improve still running diag

This improves the diagnostics message when a suite is still running and
the user attempts to run, restart or clean the suite.
rose suite-run: improve "is suite running" logic

Introduce SSH connection timeout.
Ensure that process ID is reported in preference of port file.
Merge pull request #1249 from matthewrmshin/improve-suite-still-running-diag

rose suite-run/clean: improve still running diag