[gil] Can I merge two minor fixes to header dependencies and tests for 1.7.4?

From: Mateusz Loskot (mateusz_at_[hidden])
Date: 2020-07-26 18:42:20

Dear Release Manager,

I'd like to request permission to merge these two minor fixes
into GIL's master for release with 1.74

1. Fix dynamic_image extension header dependencies
    https://github.com/boostorg/gil/pull/508

    This basically removes all-in-one #include <boost/gil.hpp
    from GIL's own headers.

2. Re-enable self containing header tests in CMake
    https://github.com/boostorg/gil/pull/509

    Minor correction to an incidental disabling of headers tests in CMake.

May I?

Best regards,
-- 
Mateusz Loskot, http://mateusz.loskot.net