Jsonmerge

* Fix RefResolutionError when merging properties with slash or tilde
characters.
* Add LICENSE file.

* Fix handling of additionalProperties (thanks to nxkb).
* Add optional debug output through the logging module.
* Fix arrayMergeById strategy when base instance has no "id" property.

* Add ArrayMergeById strategy (thanks to Sarah Bird).
* merge() and get_schema() methods now raise more specific exception
classes on error (BaseInstanceError, HeadInstanceError, SchemaError).
* Rename "unique" option for Version strategy to "ignoreDups".
* Fix duplicate entries with Version strategy even when "ignoreDups"
was True (thanks to Sarah Bird).
* Always add "type" keyword when making new objects in get_schema().
* Remove "maxItems" and "uniqueItems" keywords in get_schema() for
Append strategy.
* Use setuptools for packaging (thanks to Sarah Bird).

* First release