Extract Property classes to a separate package

[baukevdw]

Currently neat/configuration depends on neat/object for just it's property adapters. When you'd need just neat/configuration, you will get neat/object and neat/database for free. While Neat php components aim to be self-contained components as much as possible, neat/configuration could have less dependencies.

To improve the separation and dependencies of the packages the property related code could be extracted to a separate package. For example neat/property-reflection.

[annavanbiemen]

neat/configuration just received a copy of the old Property class from 0.10 to resolve a conflict when upgrading to neat/object 0.11. This makes this issue a little less urgent, but it needs to be resolved because we now have some code duplication.