[#3376] Removed usage of /e modifier with preg_replace in Zend\Filter

- Modified PregReplace to test for the "e" modifier and raise an
  exception when found
- Modified SeparatorToCamelCase to use preg_replace_callback instead of
  /e modifier
[#3376] Replace PCRE /e modifier with preg_replace_callback()

- Replaced usage of preg_replace with "/e" modifier with
  preg_replace_callback() using a closure
[#3376] Added test for new behavior

- Added a test displaying that an exception is raised when passing the
  "e" modifier in a pattern
Merge pull request #3436 from weierophinney/hotfix/3376

Hotfix/3376