bump versions
v0.155000

    [ BUG FIXES ]
    * GH #773, #775: AutoPage handler no longer renders layouts.
      (Dávid Kovács, Sawyer X)
    * GH #770: Prevent crazy race condition between the logger engine and
      other engines. This means engines now call "log_cb" to log.
      (Sawyer X)
    * App now has default name to caller package. (Sawyer X)
    * Serializers will not try to serialize empty content. (Sawyer X)
    * Lots of cleanups in Core::Request in favor of Plack::Request.
      (Sawyer X)

    [ ENHANCEMENTS ]
    * Layouts directory can be configured using 'layout_dir'.
      (Sawyer X)
    * GH #648, #760: Logger format now supports 'h', 'u', 'U', 'h', 'i'.
      They are documented but weren't really available.
      (Lennart Hengstmengel)
    * Serializers having errors will not fail if there is no logger.
      (Sawyer X)
    * Create a request object with a single argument of $env, like
      Plack::Request. (Sawyer X)

    [ DOCUMENTATION ]
    * Remove documented hack for static content because we use the middleware
      now anyway. (Sawyer X)
    * Document further the difference between splat and megasplat.
      (Dávid Kovács)
Merge branch 'release/0.155000'