- add image flip API support
- add image flip API support
- add image flip API support
- add image flip API support
- add image flip API support
- add image flip API support
- fix conflict on merge
- add new file for m4 as well
- add only once
Merge branch 'PHP-5.5'

* PHP-5.5:
  - add only once
  - add new file for m4 as well
- add constants for imageflip
- add test
- fix name for imageflip constants, consistent witht the other
Merge branch 'PHP-5.5'

* PHP-5.5:
  - fix name for imageflip constants, consistent witht the other
  - add test
  - add constants for imageflip