[20180903202725] App Export/Import and Bug Fixes

[ddollar]

Adds convox apps export and convox apps import to facilitate moving apps between racks.

• #2899 app export/import [@ddollar]
• #2902 explicit set of stickiness.enabled [@ddollar]
• #2903 allow command to be specified for gen1 start [@ddollar]
• #2905 local rack start without existing provider [@ddollar]