assigned L.geoJson to var geojsonLayer for ability to resetStyle on mouseout

see http://leafletjs.com/examples/choropleth.html for example usage.
especially used in line 51 of example10.R
added html_sub argument to renderMap for being able to use a preloaded javascript variable as the geoJson spec.features

otherwise takes way to long to round trip between R and javascript.
Added Shiny example app leaflet_chloropleth.
generalized Shiny app example leaflet_chloropleth
added Leaflet mapOpts for specifying options like worldCopyJump = TRUE

in order to repeat a copy of the data layers when panning outside
initial globe extent (< -180, > 180). see all options at
http://leafletjs.com/reference.html#map-options
commented out debug line
Merge pull request #317 from bbest/master

assigned L.geoJson to var geojsonLayer for ability to resetStyle on mous...
add rrPlot function for easier use of polycharts in IPython Notebook.
merge changes from @bbest

Merge remote-tracking branch 'origin/master'

Conflicts:
	R/renderChart.R
	inst/libraries/leaflet/layouts/chart.html
fix minor bug in leaflet layout.
bump version to 0.4
update show methods and bump version
add height and width styling for the iframe.
add rcharts.cdn as an option to globally control if js/css assets should be delivered from an online cdn.
bump version to 0.4.2
update controls html layout to bootstrap3
add preliminary support for subset filters using lodash.
add id and rChart class to iframes so that styling does not interfere with other iframes (fix #324)
add iframe- prefix to iframe id to keep things unique.
minor fix for adding id to iframes written by show.
remove old code for show and getMode