Standardise {% with ... %} tags on 1.4 syntax

All 'with' tags use the key=value syntax now for consistency.

Fixes #272

oscar/templates/oscar/catalogue/partials/gallery.html

@@ -1,7 +1,7 @@
 {% load thumbnail %}
 {% load i18n %}
 
-{% with product.images.all as all_images %}
+{% with all_images=product.images.all %}
     {# use length rather then count as the images get queried anyways #}
 
     {% if all_images|length > 1 %}

oscar/templates/oscar/catalogue/partials/product.html

@@ -12,7 +12,7 @@
     </div>
 
     {% block product_review %}
-        {% with product.reviews.all as reviews %}
+        {% with reviews=product.reviews.all %}
             {% if reviews %}
                 <ul class="review_count">       
                 {% for review in reviews %}

oscar/templates/oscar/promotions/singleproduct.html

@@ -33,7 +33,7 @@
     			{% endif %}
     		</div>
     	    {% block product_review %}
-    		    {% with product.reviews.all as reviews %}
+    		    {% with reviews=product.reviews.all %}
     		        {% if reviews %}
     		            <ul class="review_count">       
     			            {% for review in reviews %}