php7: major upgrade to 7.4.1

php7: major upgrade to 7.4.1

- remove obsolete patches and update other ones
- filter support is now available as an extension module
- php7-mod-hash: this extension is now part of the core binary
  and cannot be built as an extension module anymore
- php7-mod-gd:
  - do not use bundled libgd, but rely on external one
  - this also obsoletes dependencies and configuration options
- php7-mod-zip: requires external libzip now

Signed-off-by: Michael Heimpold <mhei@heimpold.de>