Enable whitespace control within closing blocks

This enables the ability to force whitespace to be stripped following
the end of a block statement by adding a `-` before the closing
tag. This is supported both for stripped the space at the beginning
of a block as well as stripping the space that follows a block.

tatsu_grammar.txt

@@ -29,12 +29,12 @@ raw_block_expression
 
 raw_block_start
     =
-    block_open "raw" block_close
+    block_open "raw" {SP}* block_close
     ;
 
 raw_block_end
     =
-    block_open "endraw" block_close
+    block_open "endraw" {SP}* block_close
     ;
 
 block_expression
@@ -50,16 +50,18 @@ block_start
 
 block_end
     =
-    block_open "end" name:IDENTIFIER block_close
+    block_open "end" name:IDENTIFIER {SP}* block_close
     ;
 
 block_open
     =
     @:"{%" {SP}*
     ;
+
 block_close
     =
-    {SP}* @:"%}"
+    | @:"%}"
+    | ( @:"-%}" {SP}* )
     ;
 
 line_block_expression

test_template.jinja

@@ -31,10 +31,10 @@ across lines #}
         The value will increase even more!
     {% endif %}
 {% endfor %}
-{% macro textarea(name, value='', rows=10, cols=40) %}
+{% macro textarea(name, value='', rows=10, cols=40) -%}
     <textarea name="{{ name }}" rows="{{ rows }}" cols="{{ cols
         }}">{{ value|e }}</textarea>
-{% endmacro %}
+{% endmacro -%}
 {# comment contents
 across lines #}
 <ul>