v1.2.0: improve http status handling and ease exception-to-jsonapi rendering

This is the second part of v1.1.0, adding:

• throwing jsonapi\exception which can be used to output jsonapi errors responses directly (#11)
• easily set http status on non-error responses (created, no content, redirects, etc) (#19)
• set redirect locations (#19)

Minor ones:

• manually sent http status headers, instead of jsonapi doing it automatically for you (#19)
• fixes/syncs declaration errors->send_response() with its parent (#19)

v1.1.2: fixes exceptions without file reference

Merge branch 'fix-undefined-trace-file'

v1.1.1: fixes meta objects on error responses

This fixes #9 / #14.

v1.1.0: better error handling

This release improves errors handling and processing a bit:

• error messages and exception meta data is automatically hidden on production environments, using display_errors (#6)
• exception meta data has improved display in errors responses (#7)
• content type is always send out as utf-8 (#13)
• easy constants are available for error documents, i.e. using jsonapi\base::STATUS_METHOD_NOT_ALLOWED instead of 405 (https://github.com/lode/jsonapi/pull/12/files)

Next up is an easy way to go from thrown exceptions directly to an error response. See #11.

v1.0.2: fixes null-values in data / meta

This fixes adding null values to data or meta objects. Without this fix, they were added as empty arrays.

v1.0.1: composer fixes

This fixes composer from having a self-reference to dev-master. Including via composer should work again.

v1.0.0: initial release

All the basics are here: sending out resources, collections or errors.