Code review comment for lp:~zorba-coders/zorba/identifiers

<p>Please see the <a href="../../html/data_lifecycle.html">data lifecycle
 documentation</a> about details on management and manipulation of collections.</p>
=>
<p>Please see the <a href="../../html/data_lifecycle.html">data lifecycle
 documentation</a> about details on storing nodes in collections or as documents.</p>

Computes an immutable and opaque node reference
=>
Returns an immutable and opaque node reference...

The function returns the empty sequence if the node
that is referenced was deleted.
=>
The function returns the empty sequence if the node
that is referenced does not exist (e.g. because it was deleted or the temporary node is not available anymore)

zerr::ZAPI0028
=>
zerr:ZAPI0028

Can any of the functions return ZAPI0029? If so, it's not documented. Same for ZAPI0030.

fix indentation in NodeByReferenceIterator (two spaces)
Also, add a space before and after the assignment

Fix comment in FnGenerateIdIterator => remove e.g. z0.1.1.c.50

Why is hasReference still needed?

What is the following change in node_items.cpp for?
513 - theTypesMap = new NodeTypeMap(source->theTypesMap->object_count(), false);
514 + theTypesMap = new NodeTypeMap(source->theTypesMap->size(), false);

What is the CopyMode's theCopyReference member for? Isn't it always false?