implemented toggle between standard and satellite map modes for listen view.
implemented map type toggle button for repositioning map view.
enabled functionality for disabling the like/unlike heart button in playback view if the itemInfo dictionary has an object set for the key @“isPreview”.  This is used to disable the like/unlike function when users are previewing a post they have not uploaded yet.
revised satellite/standard map view toggle button style.  Fixed bug with connection between button def and action code.
updated like/unlike api to use post method, updated parameter names.  Incorporated new heart icons into playback view.
revised upload node code to only include additional position geodata and timestamp information when there is more than one location recorded as part of the node.  Otherwise these post parameters will be omitted, as per recommendation of the server team.
minor project setting changes