Element and simpletype have same name

[kflemin]

The Tightness element is defined twice in the schema.

First use at line 262: https://github.com/BuildingSync/schema/blob/develop-v3/BuildingSync.xsd#L262
and type: links back to "Tightness", which could be interpreted as line 262 or line 14697:
https://github.com/BuildingSync/schema/blob/develop-v3/BuildingSync.xsd#L14697

PROPOSAL: change type= to "TightnessType" rather than just "Tightness".

1. change line 262 to:
   <xs:element name="Tightness" type="auc:TightnessType" minOccurs="0">
2. change line 9894 to:
   <xs:element name="TightnessFitCondition" type="auc:TightnessType" minOccurs="0">
3. change line 14697 to:
   <xs:simpleType name="TightnessType">