libcurl dependency for implementing RFC3161 timestamps

Hello,

for implementing RFC3161 timestamps in git tag, HTTP POST requests have to
be sent via libcurl. We already changed http.c to our needs.

Is there any best-practice how to introduce this libcurl dependency? There
are several options:

-As git tag is a builtin part of the main git executable, introduce a
libcurl dependency for the main executable (maybe not best-practice).

-Move git tag to a separate git-tag binary and introduce a libcurl
dependency to this new submodule.

-Create an own submodule like git-http-timestamp with a libcurl dependency
and call it from git tag and from other places where timestamp signatures
are needed.

Regards,
Phillip Raffeck
Anton Wuerfel