As suggested by @remicollet. This drastically reduces the need for our
hacks; actually, we only need the workaround to define HAVE_MBSTRING
since apparently, the extension had been build with `phpize`, and as
such the desired entry in main/php_config.php is missing.
Closes GH-15.
This is mostly standard stuff, but we need to hack around some
limitations of the tools. Most notably, `phpize` support for extension
dependencies is bad, so we add three small hacks. Furthermore, some of
the test cases are sensitive to line endings, so we ensure that
autocrlf is disabled.
Closes GH-12.