add some more warning CFLAGS, inspired by Benjamin Otte's blog post,

add some more warning CFLAGS, inspired by Benjamin Otte's blog post,

	* configure.in: add some more warning CFLAGS, inspired by Benjamin
	Otte's blog post, although none of them picked out any actual
	bugs. Annoyingly, the most interesting warnings came from
	-Wwrite-strings and -Wshadow, both of which I decided against
	keeping, because they had too many false positives.

	* libsoup/soup-cookie-jar.c (soup_cookie_jar_get_cookies): rename
	a variable to avoid shadowing.

	* libsoup/soup-message-headers.c
	(soup_message_headers_get_ranges): move a variable declaration to
	avoid a possibly-confusing shadowing.

	* tests/forms-test.c:
	* tests/header-parsing.c:
	* tests/range-test.c:
	* tests/test-utils.c: constify some "char *"s that should have
	already been const.

	* tests/get.c (find_hrefs): rename an arg whose name shadowed a
	global, to avoid possible future confusion
	(get_url): Likewise with a functional-internal shadowing.

svn path=/trunk/; revision=1222