being based on curl 0.70.0 gnurl is affected by
CVE-2015-3144
CVE-2015-3145
CVE-2015-3153
CVE-2015-3236

Import patches from curl package to fix that.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

This is definitely one of the ugliest things I ever got my
hands on. If it even did the job properly, but no, it tries
to install it's headers in /usr/include/curl collidings with
actual curl's headers. Fixed that by installing them into
/usr/include/gnurl instead. Now gnunet can use gnurl.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>