Best practices for Merger to handle segmentation

FROM: Ján Husarčík <jan.husarcik@gmail.com>

could you please add a note suggesting the best way how can the Merger
approach modified segmentation within <unit>? E.g. "join all the segments
and ignorables".

It is also unclear, how Merger should handle following valid xliff file:

<?xml version="1.0" encoding="utf-8"?>
<xliff xmlns:mda="urn:oasis:names:tc:xliff:metadata:2.0"
xmlns="urn:oasis:names:tc:xliff:document:2.0" srcLang="en-US"
trgLang="fr-FR" version="2.0" >
<file id="1">
<group id="content">
<unit id="1">
<segment state="final">
<source>1</source>
<target>1</target>
</segment>
<ignorable>
<source>some code snippet</source>
</ignorable>
<segment state="final">
<source>2</source>
<target>2</target>
</segment>
</unit>
</group>
</file>
</xliff>

If <ignorable> is not required to have <target>, it could be explicitly
stated that Merger should not expect it and still correctly process the
input.