A variety of syntax and style fixes for the Docker examples

* Made Docker a proper noun when needed.
* Fixed code syntax
* Fixed some whitespace issues
* Fixed some typos and grammar
* Tidied up some examples
Ensure container name on register
Merge pull request #2549 from dotcloud/ensure-container-name

Ensure container name on register
Merge pull request #2534 from jamtur01/examples_fixes

A variety of syntax and style fixes for the Docker examples