doc - Convert Amazon EC2 guide from text to markdown
doc - Remove notes about too many EBS reads/writes

As of June 2014 Amazon no longer charges for I/O
in the default EBS type.
This is *fantastic*. Thanks Amazon.
doc - Add note about encrypting EBS drives to amazon guide
CHANGELOG - Note amazon guide converted to Markdown
Merge pull request #50 from daveschaefer/update_amazon_doc

Update amazon doc