add Diff/Sass test for #139

Author: korny

diff/sass.expected.raydebug

@@ -0,0 +1,5 @@
+head[head(--- )filename(a/foo.sass)]
+head[head(+++ )filename(b/foo.sass)]
+delete[delete(-)  ]
+delete[delete(-)  directive(@import) string<delimiter(")content(something)delimiter(")>]
+   directive(@import) string<delimiter(")content(something else)delimiter(")>

diff/sass.in.diff

@@ -0,0 +1,5 @@
+--- a/foo.sass
++++ b/foo.sass
+-  
+-  @import "something"
+   @import "something else"