refactorings, a bug fix (#786) and improved performance for the hydration of results from polymorphic queries.

moved managed record/entity handling to the UnitOfWork. identity maps are the next. started to remove obsolete table stuff.

Removed support to imbricated query added yesterday (which fixed ticket #782). The same thing could be easily achieved without need of Doctrine support, as mentioned in comments. Dev team decided to drop this support for now, but are considering for 1.0

made sure every caller of getIdentifier can handle an array. getIdentifier now always returns an array.

Updated manual pages and changed documentation naming convention (from process to parse) to follow the API

started refactoring to final mapper structure for 1.0. different mapping strategies are factored out as separate strategy classes instead of inheritance.