Adding cost-related stuff
add pricing on the create machine wizzard, plus 2 scripts to get pricing from ec2/rackspace

show pricing per image/size combination, since ec2/rackspace charge differently for different
image for the same size. Check PRICING_ISSUES for more info and to get the pricing
update pricing json to include currency and period
update scripts to include currency
remove pricing issues notes
Merge branch 'cost-display'