Add nodejs to the small channel

(cherry picked from commit d927ce03e4ad3d65f64eb2ddad970ec08f47fffc)
linux: Update to 3.12.31
Upgrade boto to support eu-central-1 region.
Refactor EC2 image generation script. Now uses same procedure for both hvm and pv-grub
images. Root disks are now SSD backed and 20GB by default, both on hvm and pv-grub
(previously was 8GB for HVM). Added new eu-central region to the locations to copy images
to. Also the root disk for HVM instances was not deleted on termination with previous
images, this is fixed as well.
Update to latest awscli
syslog-ng: Update from 3.5.6 to 3.6.1

Also update the NixOS module, syslog-ng now automatically listens to
the systemd journal, so we don't have to set up syslog.socket.
xsession: Start the right pulseaudio binary

Fixes #4663.
Merge pull request #4683 from kirelagin/xsession-pa-fix

xsession: Start the right pulseaudio binary
thunderbird-bin: update to 31.2.0
xcodeenv: make the login keychain the default, before the generated keychain gets discarded. Otherwise, the keychain becomes corrupt
titaniumenv: make the login keychain the default, before the generated keychain gets discarded. Otherwise, the keychain becomes corrupt
Added libpcap dependency and --with-libpcap configure flag to support ip address learning
slrn: update 1.0.1 to 1.0.2
fping: set meta.platforms
Merge pull request #4685 from ehmry/slrn

slrn: update 1.0.1 to 1.0.2
tzdata: set platforms to build on hydra
tomcat: set meta.platforms
aspell: set meta.platforms
Merge pull request #4684 from aycanirican/libvirt-ip-addr-learning-support

libvirt: Added libpcap dependency and --with-libpcap configure flag to support ip...
brickd: packaged version 2.1.1