Fix passing of kernel parameters

Broken in 9ee30cd9b51c46cea7193993d006bb4301588001.  Reported by Arvin
Moezzi.
dropbox: Update to 2.4.7.

Signed-off-by: Moritz Ulrich <moritz@tarn-vedra.de>
Adding libnl 3.2.19 to use instead of the latest with ntrack

ntrack has a bug about fresher libnl compatilbility. There are no
updates since September.
Fixes ruby 2.0.0 compilation on Darwin.
Use the recommended http://cache.ruby-lang.org host to get the ruby archives
Updates ruby 1.9.3 to patch-level 484. Fixes CVE-2013-4164
Updates ruby 2.0.0 to patch-level 353. Fixes CVE-2013-4164
Updates ruby 1.8.7 to the latest patch-level. WARNING: unsupported

ruby 1.8 should be phased out as it contains security issues and is
unsupported by the ruby core team. This is the last update available but it
doesn't fix all CVEs.
Re-instate the "hydraPlatforms = []" setting accidentally overwritten earlier.
haskell-HDBC-odbc: re-generate with cabal2nix
haskell-scientific: re-generate with cabal2nix
haskell-codec-image-devil: re-generate with cabal2nix
Re-generate cuda-related expressions with recent version of cabal2nix.
libvirt: Update to 1.2.0