Make sure the user immediately sees the feedback, '.' or 'F', for a
test. If it's only in the buffer, it may gets "lost" in case of error.

Signed-off-by: schu <schu-github@schulog.org>

Fix compilation warnings in MSVC

This allows to successfully build libgit2 with waf on Windows.

When trying to inflate a buffer, a GIT_ERROR was returned when malloc()
failed.

Fix this to return GIT_ENOMEM.

git__delta_apply used to return with a generic GIT_ERROR when allocating
memory for the delta failed.

Fix this to return GIT_ENOMEM.