[master] 90c4b74 Install cache/cache_varnishd.h as part of $ABI strict

[Dridi Boukelmoune]

> Dridi, if I understand your intention correctly, you are suggesting that we
> include headers in the dist,

The header is unconditionally part of the dist, it rather moved from
noinst to includedir. This is for make install instead.

> which, during packaging, we do not put into the
> varnish "bin" package, but rather only "-dev".

Yes/no, all headers are part of the -dev RPMs/Debs as per the packaging
policies of our supported platforms.

> If this becomes the new way to got, then I would suggest that we mark in tree
> which includes to give this special packaging handling such that we do not
> need to duplicate that information for each packager.

Since $ABI vrt is a conscious choice from the VMOD author, I don't see
the point of adding one more layer of indirection.

Dridi