debian: Update to 7.6

(cherry picked from commit 1245ca3ff7b2805e7c0c09ca7e7fea7ac8bfcc5a)
Don't restart systemd-remount-fs

It's only needed during early boot (in fact, it's probably not needed
at all on NixOS). Restarting it is expensive because it does a sync()
of the root file system.

(cherry picked from commit 3b2609deec84ec71ced729f128aa9d549dcfa4f6)
Don't mount /sys/fs/fuse/connections and /sys/kernel/config

These fail to mount if you don't have the appropriate kernel support,
and this confuses NixOps' ‘check’ command. We should teach NixOps not
to complain about non-essential mount points, but in the meantime it's
better to turn them off.

(cherry picked from commit 6eaced35820f4c575dd545fb721abd74f248c8cb)
go 1.3 and darwin support
Don't restart systemd-journal-flush

It only needs to be started during boot. Starting it at other times
shouldn't hurt, except that if systemd-journald is restarting at the
same time, the latter might not have a SIGUSR1 signal handler
installed yet, so it might be killed by systemd-journal-flush. (At
least that's my theory about the dead systemd-journald instances in
the build farm...)

(cherry picked from commit 1a1442db7426262fdc23890c61c0be22cc3e1e51)
Revert "go 1.3 and darwin support"

This reverts commit 6a89670576b0e63ef08946386aa23503178f6289. It
breaks evaluation:

http://hydra.nixos.org/build/12580541
youtube-dl: upgrade to latest release
rsyncd: default read/write permissions should be nobody:nogroup

(cherry picked from commit 265c489391f0b87a962b226e00d10eac8387b48f)
rsync: sha256 for the patch was updated

(cherry picked from commit 2dfb036a307b3c68d4f1ac899f2d5458328776ff)
idris: upgrade to 0.9.14
idris-mode: upgrade to 0.9.14
linux-3.15: upgrade to 3.15.6
Merge remote-tracking branch 'official/release-14.04'
flashplayer: Update from 11.2.202.378 -> 11.2.202.394
calibre: update from 1.44.0 to 1.45.0
Merge branch 'backports!'