Iterators still under development, COntologyIterator does not yet work.
Added kTAG_NAME.
Added CUnit and CEntity: need to create address block for entity.

==> NEED TO FORMALISE SUB-UNITS LOGIC <==

Idea is to allow tags in kTAG_PATH: this means that a tag of type struct will necessarily need a tag with a scale. So concatenating tags will use the period token and this works perfectly with Mongo. Will need to implement something at the object side when committing or creating objects: a tag with periods must generate an array.

Need to quickly put data into the system...