Fix #56

Collections with one element are rendered as an array with one element instead of an object.
Note: it looks like the Json Serializer ignores empty arrays so collections with no elements are still not included in the _embbedded resource.
Tests for #56
Merge pull request #59 from danbarua/master

Fix for #56
Updated readme
Make a Representation re-serializable

When pulling a Representation from cache, embeddedResourceProperties is already populated with properties and values.  This means a second call to OnSerialize will fail if the embeddedResourceProperties dictionary isn't cleared.
Merge pull request #61 from askingalot/master

Make a Representation re-serializable
Merge remote-tracking branch 'upstream/master'

Conflicts:
	WebApi.Hal/Representation.cs