Merge tag 'v2.8.0'

v2.8.0
Fix strong-cli reference in update command help

The man page for the update command wasn't updated when strong-cli was
renamed to strongloop.
pmctl: control a node application using strong-pm
Merge pull request #167 from strongloop/feature/pmctl

pmctl: control a node application using strong-pm
package: depend on released json-file-plus 1.x

The 0.x was deprecated by author, probably well-intentioned, but just
causes npm install of strongloop to spew warning messages.
v2.9.0
Merge branch 'release/2.9.0' into production