Clean unique index in framework

[openlowcode]

The Open Lowcode framework is NOT using unique indexes, as, depending on complex properties, unique fields may not be physically unique. The option "Unique" exists, though it is not used (code sample below).

The unique option should be cleaned ( code extract from package org.openlowcode.design.data )

	public Index(String name, StoredElement simpleelement, boolean unique) {
		super(name);
		this.fields = new ArrayList<StoredElement>();
		this.fields.add(simpleelement);
	}