Support a new relative_include tag

test/source/_posts/2014-09-02-relative-includes.markdown

@@ -0,0 +1,25 @@
+---
+title: Post
+layout: post
+include1: rel_include.html
+include2: relative_includes/rel_include
+include3: rel_INCLUDE
+include4: params
+include5: clude
+---
+
+Liquid tests
+- 1 {% relative_include relative_includes/{{ page.include1 }} %}
+- 2 {% relative_include {{ page.include2 | append: '.html' }} %}
+- 3 {% relative_include relative_includes/{{ page.include3 | downcase | append: '.html' }} %}
+
+Whitespace tests
+- 4 {% relative_include relative_includes/{{page.include1}} %}
+- 5 {% relative_include relative_includes/{{   page.include1}} %}
+- 6 {% relative_include relative_includes/{{  page.include3   | downcase |   append:  '.html'}} %}
+
+Parameters test
+- 7 {% relative_include relative_includes/{{ page.include4 | append: '.html' }} var1='foo' var2='bar' %}
+
+Partial variable test
+- 8 {% relative_include relative_includes/rel_in{{ page.include5 }}.html %}

test/source/_posts/relative_includes/params.html

@@ -0,0 +1,7 @@
+<span id='include-param'>{{include.param}}</span>
+
+<ul id='param-list'>
+  {% for param in include %}
+    <li>{{param[0]}} = {{param[1]}}</li>
+  {% endfor %}
+</ul>

test/source/_posts/relative_includes/rel_include.html

@@ -0,0 +1 @@
+relative_included