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
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.
Add perl modules needed to build "slic3r"

Slic3r is a tool to convert a digital 3D model into printing
instructions for your 3D printer. I have some build/run issues with it
so add it later.

These perl modules are added:
  AlienWxWidgets
  BoostGeometryUtils
  constant-defer
  ExtUtilsCppGuess
  ExtUtilsTypemapsDefault
  ExtUtilsXSpp
  GrowlGNTP
  MathLibm
  MathClipper
  MathConvexHullMonotoneChain
  MathGeometryVoronoi
  MathPlanePath
  ModuleBuildWithXSpp
  NetDBus
  Spiffy
  TestBase
  Wx

A couple of old modules were no longer available on CPAN so I bumped
them:
  DataUUID
  ExtUtilsMakeMaker
  ExtUtilsManifest
  version
  VersionRequirements

XMLTwig fails in the test phase (it is missing a dependencies), so the
test is skipped. (How did it pass the test before?)
Merge pull request #499 from bjornfor/perl-modules

Add perl modules needed to build "slic3r"
mirrors.nix: add http://backpan.perl.org/ for old CPAN modules

It seems only the latest version of perl modules are in CPAN(?). The
BackPan claims to have a complete history of CPAN.
Update isync to 1.0.6
haskell-DAV: update to version 0.4
haskell-basic-prelude: update to version 0.3.5.0
haskell-certificate: update to version 1.3.7
haskell-conduit: update to version 1.0.5
haskell-crypto-pubkey-types: update to version 0.3.2
haskell-crypto-pubkey: update to version 0.1.3
haskell-cryptocipher: update to version 0.5.0
haskell-ghc-vis: update to version 0.7.0.1
haskell-pool-conduit: update to version 0.1.2
haskell-reflection: update to version 1.3
haskell-skein: update to version 1.0.3
haskell-uuid: update to version 1.2.12
haskell-yaml: update to version 0.8.2.4