squid: Update to 3.3.9.

Just a couple of minor bugfixes. Nothing too serious.
squid: Enable netfilter transparent mode.
Fix permissions of redirect-template directories.
kernel: updated to 3.10.16.
squid: Implement intercept mode.
core73: Add transparent proxy port configuration.
squid: Increase default number of file descriptors.
Merge branch 'next' into fifteen
core73: Fix typo in proxy configuration converter.
Merge branch 'next' into fifteen
Merge branch 'fifteen' of ssh://git.ipfire.org/pub/git/ipfire-2.x into fifteen