Support for dynamic host names.
Merge branch 'master' into dynamic_hostnames

Conflicts:
	CHANGELOG.md
	lib/ec2launcher/version.rb
More support for setting dynamic host names at boot time. Includes tests.
Rearrange test scripts.
First unit test for Route53 code.
Route53 modification tests.
Fixed revamped gemspec to include startup scripts.
First unit tests for BlockDeviceBuilder.
Completed work to support dynamic host names as well as setting the hostname at boot time.