anchor.diff:  
   The +:content-types+ key maps file extensions to MIME types.
   
  ++:content-transformers:+ maps content types to a transformation function; The CoffeeScript, Jade, and Less compilers operate by adding entries to +:content-types+ and :content-transformers+.
  +
   The +:compressable+ key identifies which content types are compressable; note the use of the +/*+ suffix to indicate
   that all text content types are compressable.
   
   File system caching is normally only enabled in development mode.
   
  -Twixt always caches the content of files in memory, after any transforming operations (such as compiling CoffeeScript to
  -JavaScript). 
  +Twixt always caches the content of files in memory, after any transforming operations. 
   In development mode, checks are enabled to refresh the cache when underlying files are modified; 
   in production, no such checks occur as it is assumed that all such assets are stable
   (until the entire application is re-deployed).
  
positive.code: (def default-options
    {:path-prefix        "/assets/"
     :root               "META-INF/assets/"
     :content-types      (merge mime/default-mime-types {"coffee" "text/coffeescript"
                                                         "less"   "text/less"
                                                         "jade"   "text/jade"})
     :compressable       #{"text/*" "application/edn" "application/json"}
     :cache-folder       (System/getProperty "twixt.cache-dir" (System/getProperty "java.io.tmpdir"))
  ----
  
negative.code: The checksum has a optional "z" prefix; this indicates a GZip compressed resource.
  Twixt detects if the client agent supports GZip compression (via the +Accept-Encodings+ header).
  In addition, compression is only applied to specific content types, such as "text/html" and "application/edn".
  Most binary formats, including fonts and images, are already compressed.
  
  Because of this, when referencing assets inside your templates, you must pass paths (relative to +META-INF/assets+)
  through Twixt to get URIs that will work in the browser:
  