Change notation of property names.

Property names will now follow the eBay notation in the XML.
Merge branch 'property-names' into develop
Change how service objects are constructed.

No longer need to pass a HttpClient when creating a service object.
Merge branch 'service' into develop
Fix PHPDOC for property names.

PHPDOC for property names now uses Fully Qualified Class Name
(FQCN) so that autocomplete for IDEs work.

E.g.

Before
@property Foo\Bar $example

After
@property \Foo\Bar $example
Merge branch 'phpdoc' into develop
Correct PHPDOC for Enum and Array properties.

Before:
@property string $strings
@property \DTS\Enum(string) $enum

After:
@property string[] $strings
@property \DTS\Enum $enum
Merge branch 'phpdoc' into develop
Update README and add CHANGELOG.
Merge branch 'readme' into develop
Fix link to CHANGELOG.md
Update to API version 871.
Merge branch 'api-871' into develop
Add link to SDK website.
Merge branch 'composer' into develop
Update code for 0.1.0 release.
Merge branch 'release-0.1.0'