Eliminate curl binary

[Stepan Kasal <kasal@ucw.cz>]

Hello,

git source code uses curl (the binary) on exactly one spot:
git-clone.sh
I would welcome if that spot were rewritten so that git would no
longer require curl, only libcurl.

(I clashed with a design flaw of curl cmd-line interfaace, so I'd
like to uninstalle it.  ;-)  Nothing against libcurl.)

I apologize that I'm not providing a patch, and hope that this quick
bug report (enhancement request) is better than doing nothing.

OTOH, I might write a patch later, so quick hints are welcome.
(A git-* binary shall be called insted of curl in git-clone.sh; shall
it be written from scratch, or is there a git-*.c source which can be
bended for this purpose?)

Have a nice day,
	Stepan Kasal