Fixes to install process

Having applied the fixes in this pull request, I managed to get down to just 2 Salt errors:

    ----------
              ID: get_mapstarter
        Function: cmd.run
            Name: dest=mapstarter
    wget -nv http://gis.researchmaps.net/sample/map-starter.zip -O $dest.zip
    mkdir $dest
    unzip -o $dest.zip -d $dest
    # If the unzipped archive contains exactly one directory, move it up a layer:
    if [ `ls $dest | wc -l` == 1 ]; then
      subdir=`ls $dest`
      mv $dest/$subdir/* $dest/
      rmdir $dest/$subdir
    fi
     
          Result: False
         Comment: Desired working directory "/usr/share/mapbox/project" is not available
         Changes:   

And:

    ----------
              ID: osrm_reindex_bicycle
        Function: cmd.wait
            Name: ./osrm-extract extract.osm.pbf # creates .names, ., .restrictions
    ./osrm-prepare extract.osrm # creates .fileIndex, .hsgr, .nodes, .ramIndex, .edges
    sleep 2
    test -f extract.osrm.hsgr || ( echo "OSRM extract failed somehow." && exit 1 )
    pkill -f 'osrm-routed.*-p 5010' # Make sure we kill the right instance.
    # nohup ./osrm-routed -p 5010 -t 8 extract.osrm > /dev/null 2>&1 & 
    /mnt/saltymill/log.sh "OSRM index for profile 'Bike' rebuilt."
     
          Result: False
         Comment: Command "./osrm-extract extract.osm.pbf # creates .names, ., .restrictions
                  ./osrm-prepare extract.osrm # creates .fileIndex, .hsgr, .nodes, .ramIndex, .edges
                  sleep 2
                  test -f extract.osrm.hsgr || ( echo "OSRM extract failed somehow." && exit 1 )
                  pkill -f 'osrm-routed.*-p 5010' # Make sure we kill the right instance.
                  # nohup ./osrm-routed -p 5010 -t 8 extract.osrm > /dev/null 2>&1 & 
                  /mnt/saltymill/log.sh "OSRM index for profile 'Bike' rebuilt."
                  " run
         Changes:   
                  ----------
                  [there's more]
    
I suspect the former is bogus; possibly that terribly nasty 'ls' test you're doing. Will investigate later. The latter I suspect is what you mentioned about OSRM failures on Trusty.

I'm still kind of cargo-culting this install, so not sure exactly how everything fits together yet, but I'm working my way through the Salt doco so I can understand how it all works, and hopefully make some of the code cleaner and more robust.