* Register additional handlers from wrappers

* Return zval instead of parse frame

* Use parse frame

* Update upb

* Lazily create wrapper messages

* Fix a segment fault

Need check type of field before getting submsg def

* Avoid expanding during serialization and direct access

* Fix a bug that getXXXUnwrapped returns null for string

* Implement writeWrapperUnwrapped

* Add more tests

* Fix oneof wrapper parsing

* Fix get oneof field

* Avoid expansion for oneof wrappers

* Fix bug

* Fix a bug that in php7 variable is defined out of scope

* Fix broken tests
 * Update upb to fix Timestamp conformance tests
 * Fix segmentation fault for oneof wrapper fields

* Fix encoding/decoding top level wrapper values

* Add type checking for write wrapper value in php7

* Fix zts build

* Fix the bug that readWrapperValue uses parent message's layout to access wrapper value

* Fix wrapper in map