ENH: port list -> array code from v0.3.x branch
ENH: port list -> array code from v0.3.x branch

 - do not need to move the array -> list code over as this
   is being done by the RunEngine currently

hhslepicka/metadatastore,hhslepicka/metadatastore,ericdill/databroker,tacaswell/metadataStore,ericdill/databroker,arkilic/metadatastore,NSLS-II/metadatastore,arkilic/metadatastore,tacaswell/metadataStore,NSLS-II/metadatastore