net: ipv6: allow choosing optimistic addresses with use_optimistic

The use_optimistic sysctl makes optimistic IPv6 addresses
equivalent to preferred addresses for source address selection
(e.g., when calling connect()), but it does not allow an
application to bind to optimistic addresses. This behaviour is
inconsistent - for example, it doesn't make sense for bind() to
an optimistic address fail with EADDRNOTAVAIL, but connect() to
choose that address outgoing address on the same socket.

Bug: 17769720
Bug: 18609055
Change-Id: I9de0d6c92ac45e29d28e318ac626c71806666f13
Signed-off-by: Erik Kline <ek@google.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Revert "block, bfq: add Early Queue Merge (EQM) to BFQ-v7r6 for 3.10.8+"

This reverts commit 17f27d6ffcccb3f79de4b25953bcb57a78461c35.
Revert "block: introduce the BFQ-v7r6 I/O sched for 3.10.8+"

This reverts commit 993d65df4ed1224248d2fdd556145ec569d5edab.
Revert "block: cgroups, kconfig, build bits for BFQ-v7r6-3.10.8+"

This reverts commit e22a1026eaec7e6c00207e69224139812a77565f.
Revert "staging: binder: Change binder mutex to rtmutex."

This reverts commit a50bd718cb053376bd2706eb958d750cec323253.
ramdisk: improve symlink redundancy prevention