Add (string) case in encodeSecureCookie call to hash_hmac

Per http://php.net/manual/en/function.hash-hmac.php, the second argument to hash_hmac is supposed to be a string. HHVM (http://www.hhvm.com) is more strict about checking the arguments.
Add default return value for request data

Allow overloading of the default return value of NULL when
requesting request data.

Example:
  http://host/action?foo=bar&abc=123

  $app->request->get('foo')        -- [bar]
  $app->request->get('bar')        -- [NULL]
  $app->request->get('bar', false) -- [FALSE]
Controller as \class::method
[] -> array()
.travis.yml - add PHP 5.5
Add property typehints for proper IDE support.
Fix ordering
Don't rely on system setting for error_reporting level
add 418 HTTP status code

See RFC 2324
https://tools.ietf.org/html/rfc2324
Remove redundant call to setTemplatesDirector method.
Pass through 'templates.path' to view object singleton.
Allow local data to be passed into a template during rendering.
Remove mcrypt dependency
fix [] -> array()
change separator "::" -> ":"
Bump version number
Try running unit tests on HHVM
Set default timezone for unit tests
Merge branch 'release-2.4.1' of github.com:codeguy/Slim into release-2.4.1