squid: Update to 3.5.17

  'squid 3.4.14' is rather old and the time could be right to test the
current version '3.5.17'.

And perhaps this could fix a few problems, reported on the IPFire-Forum.

For the records:
Building was smooth - test installation is running - 'ipv6' is DISABLED here.

Please note: using a similar 'lfs' as in 3.4.14', you get a startup warning in
'cache.log':

***SNIP***
squid BCP 177 violation. IPv6 transport forced OFF by build parameters.
***SNAP***

This warning is triggered if 'squid' was built with configure-option
"--disable-ipv6".

Details (regarding the initial 3.5.7) see:
http://squid-web-proxy-cache.1019090.n4.nabble.com/squid-announce-Squid-3-5-7-is-available-td4672623.html
http://blog.gmane.org/gmane.comp.web.squid.general/page=17
http://www.rfc-editor.org/info/rfc6540

***SNIP***
* IPv6: improve BCP 177 compliance

Since early 2012 it has been mandatory for new or upgraded Internet
connected machinery and software to support IPv6 ad use it in preference
over IPv4.

Squid IPv6 behaviour has followed these practices since well before the
guidelines became a BCP. Over the years it has also grown into a
well-tested and widely used feature.

The --disable-ipv6 build option is now deprecated. It is long past time
to fix whatever network brokenness you may have that made it look
attractive in past years.

Squid-3.5.7 and later will perform IPv6 availability tests on startup in
all builds.

 - Where IPv6 is unavailable Squid will continue exactly as it would
have had the build option not been used.

   These Squid can have the build option removed now.

 - Where IPv6 is detected but --disable-ipv6 prevents use Squid will log
"WARNING: BCP 177 violation".

    Please test whether you can rebuild with IPv6 enabled.
***SNAP***

But: enabling 'ipv6' resulted in errors ('cache.log'):
... 2016/04/22 01:58:54 kid1| 
DiskThreadsDiskFile::openDone: (2) No such file or directory 2016/04/22 01:58:54 kid1| 
/var/log/cache/00/00/0000005F
...

I tracked this down to corresponding "TCP_SWAPFAIL_MISS/200"-messages in
'access.log', still investigating.

Testers are welcome, please take a look at:
http://people.ipfire.org/~mfischer/squid/3.5.17/ (two versions!).

If anyone wants to know the complete changelog since '3.4.14' - take a look at:
https://ftp.mirrorservice.org/sites/ftp.squid-cache.org/pub/squid/squid-3.5-ChangeLog.txt

Best,
Matthias

Signed-off-by: Matthias Fischer <matthias.fischer@ipfire.org>
---
 config/rootfiles/common/squid | 238 ++++++++++++++++++++++++++----------------
 lfs/squid                     |  35 +++----
 2 files changed, 162 insertions(+), 111 deletions(-)