scrips/functions: fix downloads using curl

By default curl doesn't folow redirects. This breaks sourceforge downloads.
Add the -L option to curl to fix this.

Curl also downloads the html as a file even when it gets a 404. This breaks
http downloads when using the failback system. Add the -f option to curl to fix
this.

Signed-off-by: Richard Strand <richard.strand@icomera.com>

 reporter_name="Nye Liu"

 reporter_url="http://sourceware.org/ml/crossgcc/2008-10/msg00046.html"

 reporter_comment=""