git: add subpackage for http(s)/ftp(s) commands

git: add subpackage for http(s)/ftp(s) commands

This patch add a new package, git-http, that contains all
http related commands (and ftp as extra). All http/ftp
depends on libcurl. Even without SSL suport in libcurl,
git compiles and it returns an informative error only
at runtime.

The use of symlinks now are trigged using NO_INSTALL_HARDLINKS env
and not based only on Makefile patch.

imap-send was kept builtin and idependent of curl (just as it was
before)

Template files, which are not necessary, where removed.

Signed-off-by: Luiz Angelo Daros de Luca <luizluca@gmail.com>