Create ERT-based test for issue #9.

This allows regression testing without needing manual inspection.
ERT test for issue #8.
ERT tests for issues 14, 16, and 18
ERT test for ejmr/php-mode#19
Require `php-mode` in `php-mode-test.el`, duh.
ERT tests for remaining example files.

This should close ejmr/php-mode#60
Mark tests 9, 14, and 19 as expected failures.

This makes all tests pass or fail expectedly for the current version. As bugs
are fixed, the expectation of failure can be removed.
Merge branch 'haxney/ert-tests'

* haxney/ert-tests:
  Mark tests 9, 14, and 19 as expected failures.
  ERT tests for remaining example files.
  Require `php-mode` in `php-mode-test.el`, duh.
  ERT test for ejmr/php-mode#19
  ERT tests for issues 14, 16, and 18
  ERT test for issue #8.
  Create ERT-based test for issue #9.
Add documentation about the automated unit tests to the README
Update php-mode-modified for the new automated unit tests