CP-7272: update base kernel patches to 3.10.25.

Remove patches that are in 3.10.25 and rebase many of the netback
ones on top of 3.10.25.
CP-7272: replace two Xen patches with equivalents from upstream.
CP-7272: net device allocation patch is now in 3.13-rc1.
CP-7272: update to 3.10.26.
CP-7272: Rename the netback patches to match the convention for backports
CP-7272: update to 3.10.27.
CA-123766: Commit 92bb73ea2c434618a68a58a2f3a5c3fd0b660d18 fixed a race
in tun_select_queue() but similar code is present in netdev_tx_t tun_net_xmit()
Merge commit '503e4df880f6a7f46ed32477f137a559b59a6cd8'
CA-123766: replace divide with multiple as suggested upstream
CA-118215: disable fnic driver tracing by default

The last FNIC_TRACE() looks unsafe in fnic_queuecommand_lck() since it
is tracing requests that have been submitted and (I suspect) completed
and freed on another CPU.  We have no need for the fnic tracing so
just disable it by default.