Merge pull request #100 from letr0n/master

HasOnePolymorphic and HasManyPolymorphic with tests
Renamed Hydrator class to Query
Cleaning up [skip ci]
Cleaning up
Cleaning up [skip ci]
Cleaning up
Cleaning up
Cleaning up
Cleaning up
Cleaning up
Bugfix
Cleaning up
Moved Config class to its own namespace
Moved error classes to their own namespace
Added acceptable*() methods to Request class
Added tests
Now works with a space after the ";" in the accept headers
Added some comments
Removed unnecessary function call
No need for this parameter