Re-add ApiProperty.dataType which was accidentally removed with 3f95978b

As of 3f95978b, compilation fails with the message:
  SwaggerJsonSchemaProvider.scala:205: error: value dataType is not a
  member of com.wordnik.swagger.annotations.ApiProperty

This commit re-adds the dataType field and now it builds and all tests
pass.
Merge pull request #147 from shawnlauzon/fixApiProperty

Re-add ApiProperty.dataType which was accidentally removed with 3f95978b
fixed response headers
added headers
updated to play 2.1
added per #149
updated to use utf-8
fix for #142
fix test failure
[maven-release-plugin] prepare release swagger-project_2.9.1-1.2.1
[maven-release-plugin] prepare for next development iteration
added support for @JsonProperty and @JsonIgnore per #152
Support @JsonAutoDetect to enable/disable methods and fields.

The current system uses only public fields and methods, and there isn't
a very good way of changing this. This commit adds support for
@JsonAutoDetect, which is used by Jackson to configure what types of
fields and methods are supported.

Caveats:
* Annotation is only supported at class level
* The creatorVisibility is not supported
* Visibility.PUBLIC_ONLY is the default visibility, which is different
  from Jackson, but more consistent with the existing Swagger.

I considered instead using XmlAccessType, but since Swagger supports
both Jackson and JAXB annotations, decided to use the one that worked
better for us.

Finally, I did not add unit tests for this. If this seems like a good
direction, I will write some unit tests and include in this commit.
Merge branch 'json_auto_detect' of https://github.com/shawnlauzon/swagger-core into json_auto_detect