make layerChooser available to plugins so they can add layers of their own
further refine tooltips to be more visible against the map
add draw plugin. See #135
add draw plugin description
color Leaflet marker icon accordingly
Merge branch 'gh-pages' of github.com:breunigs/ingress-intel-total-conversion into gh-pages
fix error when drawing polylines
allow dragging of markers
fix left over typo from previous commit
draw lines between portals and resonators (fixes #88 #151)

The lines look great against a dark background but are barely visible against
OSM CloudMade Minimal. Not sure what could be done about that though, other
than drawing differently for each.