Throw an error if an Addon does not specify a name.

We use a generated name when an addon just uses the default
implementation (meaning it doesn't need an index.js), but if you export
an object that does not contain `name` you get very weird and bizarre
errors (took me a bit to track it down).
Revert "Adds a util function"
Merge pull request #1743 from stefanpenner/revert-1740-instantiate-util

Revert "Adds a util function"
Making use of Core object
Merge pull request #1744 from twokul/command-core-object

Making use of Core object
[Bugfix nicething] testem doesn’t like custom base url’s so lets give a good default.
Do not redefine passed in argument

Causes deopt in v8.
Merge pull request #1753 from twokul/argument-redefine

Do not redefine passed in argument
Merge pull request #1748 from stefanpenner/happy-testem-with-base-url

[Bugfix nicething] testem doesn’t like custom base url’s so lets give a ...
Merge pull request #1741 from rwjblue/throw-an-error-if-name-is-not-specified

Throw an error if an Addon does not specify a name.
Adds tests to ensure that all pre-1.0 package versions are locked
Merge pull request #1754 from brzpegasus/version-lock

Adds tests to ensure that all pre-1.0 package versions are locked