Support for nullable annotations, closes #145
Issues closing the curl client, closes #146
Proxy classes' signatures cant import type hintings, closes #147
Add the ability to specify query language.

It is now possible to optionally specify which query language to
use when sending queries to OrientDB using HttpBinding::query()
and HttpBinding::command().

This commit introduces a breaking change in the public binding
API since since we had to add a new $language parameter to both
the above mentioned methods and move $database as the last one.
Enable server side scripting in OrientDB configuration.

This will be useful in the future to write functional tests
covering the subject.
added findOneBy* and findBy* magic methods in repositories, closes #149
fetchplans for repository classes, closes #150
Link lists|sets|maps were broken due a wrong default value in the findRecords signature.
Casting links was fixed, was returning ValueProxies of Proxies of objects, the 2nd proxy was, ofc, too much.
closes #99
revisit Rebuild Formater
Major performance improvements into the Mapper:
* introduced doctrine cache for retrieving annotations
* introduced a simpler cache for casting
* introduced a simpler cache for class mapping
* inflection is cached with a simple cache