nikic/include-interceptor

Initial release. Relative to https://github.com/icewind1991/interceptor 0.3.0, the following changes have been made:

• Remove support for PHP < 7.1. Add type annotations.
• Fix notice that is thrown every time a non-absolute path is used outside include. (Main motivation for this fork...)
• Don't call interception hook if the included file does not exist.
• Perform pseudo-realpath resolution for phar:// paths to make filtering work.
• Change the interceptor API to remove the FileFilter dependency. There now is only a single hook that both decides whether it wants to intercept and performs the interception. FileFilter is still provided as an optional convenience.
• Add support for white/blacklisting single files in FileFilter.
• Don't filter extensions by default in FileFilter.
• Allow overriding overridden stream protocols in Interceptor constructor.