Merge pull request #153 from ThijsWouters/master

HighChart#to_ary returns a Hash
update som aditional comments in README
Update to latest Highcharts and Highstock
Merge pull request #155 from pstengel/update-3.0.7

Update to latest Highcharts and Highstock
share highcharts:update rake task for gem and rails host app
bump version