Added support for markdown in heading cells when they are nbconverted.

IPython/nbconvert/templates/basichtml.tpl

@@ -62,7 +62,7 Out[{{cell.prompt_number}}]:
 <h{{cell.level}}>
 {% set source = cell.source | replace(' ','_') %}
 <a class="heading-anchor" id="{{source}}" href="#{{source}}">
-  {{cell.source}}
+  {{cell.source | markdown| rm_fake}}
 </a>
 </h{{cell.level}}>
 </div>

IPython/nbconvert/templates/markdown.tpl

@@ -61,7 +61,7 $$
 
 {% block headingcell scoped %}
 
-{{ '#' * cell.level }} {{ cell.source}}
+{{ '#' * cell.level }} {{ cell.source | wrap(80)}}
 
 {% endblock headingcell %}
 

IPython/nbconvert/templates/rst.tpl

@@ -64,7 +64,7 Out[{{cell.prompt_number}}]:{% endif %}{% endblock output_prompt %}
 
 {% block headingcell scoped %}
 {%- set len = cell.source|length -%}
-{{ cell.source}}
+{{ cell.source | markdown2rst}}
 {% if cell.level == 1 %}
 {{- '=' * len }}
 {%- elif cell.level == 2 %}