{% set columns = {'fqr':'Full reference',
                  'name':'Name',
                  'type':'Type',
                  'desc':'Description',
                  } -%}

Changed features:
{% for item in columns|sort -%}{{ columns[item] }}|{%- endfor -%}
{%- for item in columns|sort -%}{{ columns[item] }}|{%- endfor %}

{% for fqr in data.sourcedata.features|sort -%}
    {%- if fqr in data.targetdata.features and not data.sourcedata.features[fqr]._compare(data.targetdata.features[fqr], columns.keys()) -%}
        {%- for colname in columns -%}
            {{- data.sourcedata.features[fqr][colname] }}| 
        {%- endfor -%}
        {%- for colname in columns -%}
            {{- data.targetdata.features[fqr][colname] }}| 
        {%- endfor %}
{% endif -%}
{%- endfor %}

Only in sourcedata:
{% for fqr in data.sourcedata.features|sort -%}
    {%- if fqr not in data.targetdata.features -%}
        {%- for colname in columns -%}
            {{ data.sourcedata.features[fqr][colname] }}| 
        {%- endfor %}
{% endif -%}
{%- endfor %}

Only in targetdata:
{% for fqr in data.targetdata.features|sort -%}
    {%- if fqr not in data.sourcedata.features -%}
        {%- for colname in columns -%}
            {{ data.targetdata.features[fqr][colname] }}| 
        {%- endfor %}
{% endif -%}
{%- endfor %}