Half-orm

* [field][fix] Unsetting a Field by assigning None to it did not work anymore. (ef0735c)

* Do not include partitioned tables in pg_meta. (04f6637)
* [doc][WIP] Add documentation in model and relation modules. (2040c95)
* [model] move relation class factory from relation to model. (eee6d05)
* [relation] Remove count method. (f3577c1)
* [model] get_relation_class raises MissingSchemaInName. (b3c9702)
* [model] Remove unused parameters dbname and raise_error from Model constructor. (95a3153)
* [docs][pg_meta][field][model][BREAKING CHANGE] Privatize some public methods. (a756443)

* [relation] Allow fields names to be passed to Relation.get method. (93caa77)
* Add Model.execute_function and Model.call_procedure methods. (35215b3)
* Switch development status to beta. (74d3c67)
* [test] Don't reuse instances of Relation objects in tests. (0e137ce)
* [repr] Fix duplicates in unique constraints. Update README. (a91678e)

New features

* You can now trigger the execution of PostgreSQL stored procedures and
functions by using `Model.execute_fonction` and `Model.call_procedure` methods.
* You can now pass fields names to The `Relation.get` method:
py
gaston = Person(last_name='Lagaffe', first_name='Gaston').get('id')

* Fix Relation constraints representation. (c7beac7)
* Add deprecation warning for FKEYS module variable. (286a84c)
* [test] half_orm.hotest.hotAssertIsUnique takes a list of fields names. (283aefd)

Breaking change

The `FKEYS` module variable (undocumented, mainly used with half_orm_packager) is
deprecated. It is replaced by the `Fkeys` Relation class attribute.

* [doc] Improve README. (3363818)
* [WIP][fkeys] Make fkeys chaining possible. (62bf465)
* [fkeys][documentation] Add info about Fkeys class attribute in the relation class documentation. (0bc5af7)
* [WIP] Switch FKEYS module variable to Fkeys class attribute in halftest package (hop next release). (fb15769)
* [WIP] Allow constraint in joined objects. (61cd3f6)
* [test] Add tests for Relation._schemaname and Relation._relationname. (6845941)
* [relation][WIP] take into account the Fkeys attribute for a class inheriting from get_relation_class (00ecffe)
* [meta] Use tuple instead of normalized fqrn for key in metadata. (347fd98)

* Use pg_meta qrn manipluation fonctions in relation and fkey modules. (45c9836)
* [test] Test Model._reload. (99f7c64)
* [model][meta] Move qrn manipulation fonctions to pg_meta. (29def79)
* [meta] Rename pg_metaview to pg_meta. (558d328)
* [meta] Remove Model._metadata attribute. (f2a68b3)

Note

This release fixes some problems with half_orm_packager (pre-alpha).