PHP: use php7_wrapper to reduce duplicated codes on v1.0.x branch(second part)

PHP: use php7_wrapper to reduce dup-codes on v1.0.x branch

update copyright

Add new file to build.yaml

Fix a memory leak in Node call credentials

Fix AuthSample crash on startup

node: fix health check package.json template

Fixed typo in Node health check package.json

PHP: update package.xml and composer.json

Remove non-manylinux linux .whl artifacts

Enable server reflection in c++ examples

Fix cygrpc test

Make default log verbosity ERROR, run tests with DEBUG

Conflicts:
	tools/run_tests/run_tests.py

Cherrypick #7319 into v1.0.x

Backport delayed write into v1.0.x branch

[support PHP7 on v1.0.x branch] control code by version of PHP macro

Upgrade virtualenv pip in Python docgen

Correct shell scripting mistake in node package generation code

grpc_args doxygen docstrings

Also ignore the docgen-generated directories under doc/.