Use 'GET' method instaed of 'HEAD', since some proxy server doesn't work

Use 'GET' method instaed of 'HEAD', since some proxy server doesn't work
with 'HEAD' method.

Actually, when http.c was born, it used 'GET' method.  This was changed
with revision 1.4 (which was submitted as PR: 21449).  I've confirmed
to Philipp Mergenthaler <philipp.mergenthaler@stud.uni-karlsruhe.de>,
the submitter of PR: 21449, and it's absolutely OK that we can use
GET method.

Add missing 'FreeBSD' tag, and copyright notice.  This file is originally
submitted by PR: 11316; I've contacted to the PR originator to submit it.

PR:		32238
Submitted by:	Christoph Weber-Fahr <christoph.weber-fahr@arcor.de> (patch),
	and Philipp Mergenthaler <un1i@rz.uni-karlsruhe.de> (copyright)
MFC after:	1 week