firefox: Fix build on 32-bit by using the gold linker
python3Packages.{pagerduty,sipsimple}: disable
firefox: Fix evaluation on non-Linux

Actually we only support Firefox on Linux, but we hit the “attribute
‘gcc.override’ missing” error before the platform check.
New package: safe-rm-0.11
emacs24Macport: 23.4-mac-4.8 -> 24.4-mac-5.0
Merge pull request #4607 from k0ral/safe-rm

New package: safe-rm-0.11
structured-haskell-mode: use haskell-src-exts 1.15
emacs-magit: update to 1.2.1
lttng-modules: update to 2.6.0-rc1
structured-haskell-mode: actually fix
lttng-modules: disable on 3.12 kernel
twitter-bootstrap: use fetchFromGitHub
haskell-basic-prelude: update to version 0.3.10
haskell-binary-conduit: update to version 1.2.3
haskell-classy-prelude-conduit: update to version 0.10.1
haskell-classy-prelude: update to version 0.10.1
haskell-ekg: update to version 0.4.0.4
haskell-extra: update to version 0.3.1
haskell-fay: update to version 0.21.0.2
haskell-fb: update to version 1.0.7