#96089: added support for filtering by circles in addition to poligons, needed by the walking distance tool.
#96089: Added support for adding circles around the stations as filters for the tool.
#96089: changes in methods and attribute names.
Merge pull request #35 from luisromangz/96089-AddedFilteringByDistanceToTubeStations

#96089 added filtering by distance to tube stations
#95076: Added glyphicons freely avalaible pngs to the project.
#95076: Added marker clustering library and applied to the results shown in the map. Also changed the icons shown for the results using a little nice home from glyphicons.
Merge pull request #36 from luisromangz/95076-MarkerClusteringAndNewIcons

#95076 marker clustering and new icons