add test case and fix for issue #53
add test case and fix for issue #54
add media test cases and fix for issue #24 (but nested format output is slightly broken)
a mixin can have a non-block in any position
Merge pull request #58 from robocoder/patch-53

add test case and fix for issue #53
rebuild tests
simplify fix for #53
Merge pull request #59 from robocoder/patch-54

add test case and fix for issue #54