Add the support of launching spot instances in "amazon-ebs" AMI
Clean up code via "go fmt"
Add "spot_price" param into template processing
When unexpected state found in waiting, notify the caller func with a correct error message
Add the cleanup for existing spot request
Save the spot request before waiting for its active state
Enable the spot_price in "amazon-instance-store" AMI
Add the document for the new spot_price parameter
Merge branch 'add-spot-instance-support' of github.com:henrysher/packer into henrysher-add-spot-instance-support

Conflicts:
	builder/amazon/common/run_config.go
	builder/amazon/ebs/builder.go
	builder/amazon/instance/builder.go
Merge branch 'henrysher-add-spot-instance-support'