Added support to load entities with inheritance

The method "getDeclaredId" from EntityManager on line 123 can't get the
id attribute from a mapped super class.
This change only support InheritanceType.SINGLE_TABLE.
The ParameterLoaderInterceptor was corrected and there are new test for
validate it.
Now is possible load entiites with inheritance and wich inherit from
MappedSuperClass.
The ParameterLoaderInterceptor was corrected and there are new tests for
validate it.
Now is possible #8 loading entities with inheritance and entities which
inherit from MappedSuperclasses.
Correcting indentation with spaces.
Indentation was corrected with tabs.
Imports were organized.
Merge pull request #11 from raphait/vraptor3

Added support to load entities with inheritance for Vraptor3