[#4624] Fix notice

- Factory embedded in ViewHelperManagerFactory was not checking if
  services and/or array keys existed prior to accessing them.
[#4629] Allow caching null values from callbacks

- Implemented test case for #4629
- Used fix suggested in original report
Merge branch 'pull/4622'
Close #4622
Allow specifying router class to use

- Allows usage of TranslatorAwareTreeRouteStack via configuration now:

  'router' => array(
      'route_class' => 'Zend\Mvc\Router\Http\TranslatorAwareTreeRouteStack',
      'routes' => array( /* ... */ )
  )

- Also possible to use alternate console routers this way
fixed #4552: Zend\Cache\Storage\Adapter\Wincache::getItem() have to return NULL in cases of not found items
removed checks of not existing class Zend\Math\BigInteger
Punycode decoding fails if encoded string has not hyphen
Incorporate feedback
[#4618] Fix fromReflectedFileName()

- method was not properly detecting when a file does not exist, in part
  due to using no longer implemented methods of FileReflection.
[#4618] Typo in variable name
[#4618] File check in include_path can't be do as part of the fix because $includeIfNotAlreadyIncluded lost his functionality
[#4618] Fix test assets
[#4618] PHP files needs at least two lines
Merge branch 'hotfix/4618'

Close #4618
Merge branch 'hotfix/4618' into develop

Forward port #4618
Merge pull request #4632 from marc-mabe/hotfix/4552

fixed #4552: Wincache::getItem() have to return NULL in cases of missing items
Merge branch 'hotfix/4632'

Close #4632
Fixes #4552
Merge branch 'hotfix/4632' into develop

Forward port #4632
Can't return false whithout call parent::isActive
Merge branch 'hotfix/4634'

Close #4634