bluez5: add experimental expression for bluez5

bluez5 has many changes relative to bluez4. Most notable are dependency on
linux-3.4 and new dbus API.
bluez5: mark bluez5 with loPrio
Update gnutls to 3.1.10.
notmuch: patch source to use full path of gpg2

gets rid of the dependency on the old gnupg1. and enables decryption
even if the gpg binary is not in the users environment.

warning: i don't know whether the switch from gnupg1 to gnupg
introduces any incompatibilities. this is a works for me patch.
gdb: update to 7.6
Make it possible to enable vbox extension pack easily from nixpkgs config

Signed-off-by: Shea Levy <shea@shealevy.com>
Add doxypy nixpkg

Signed-off-by: Shea Levy <shea@shealevy.com>
sqlite 3.6.23.1: Remove (unused)
DBI: Update to 1.625
sqlite: Update to 3.7.16.2
sqlite: Don't include the last component of the version in the filenames

SQLite point releases are conservative, so we don't need to refer to
SQLite versions at this level of precision.
sqlite: Make 3.7.16 the default again

I've fixed the Hydra problem and the DBIx::Class issue is only a
problem in its test suite, apparently.
nixUnstable: Update to 1.5.2pre3091_772b709
mkvtoolnix: upgrade to 6.2.0
linux-3.8: upgrade to 3.8.10
linux-3.9: upgrade to 3.9.0
linux-3.9: no longer marked as RC, updated "latest" reference.
Adding go 1.1 beta
Merge pull request #478 from falsifian/update_gnutls_clean

gnutls: update to 3.1.10 (security fix)
Virtuoso: upgrade to 6.1.6