git_remote_add -> git_remote_create
git_remote_new -> git_remote_create_inmemory

fetchhead reading/iterating

netops: on SSL teardown only send shutdown alert

Make `goto cleanup` more consistent

RFC: Some cleanups/features in CMakeLists.txt

Fix some leaks in tests

Also adds some asserts.

... so we can clean up correctly.

Instead tell MSVC to group the source files by directory.

- Also document the -DSTDCALL even better.

With the src/compat/*.c glob removed, there is no longer a difference to
the default globs we use for the IF( UNIX ) case.

This directory doesn't exist.

Up to now, on windows we don't even bother to look if the user has a zlib
available somwhere.

In almost all larger commercial projects i've participated in, it was not
at all uncommon to have such a dependency somewhere in the source tree and
use it whereever required.
Searching for it, even if it's unlikely to be present, allows for such a
scenario (i.e. by prefilling the CMake-Cache).

There may be some question about whether this is likely to be needed
at all, but that's above my head at the moment.