Add isPath to trivial.nix

Signed-off-by: Shea Levy <shea@shealevy.com>
Revert "Add isPath to trivial.nix"

This breaks NixOS, and I don't actually need it, so someone who needs it
can bring this back without breaking NixOS :)

This reverts commit 2742087bdd092d77083dc99cdafb6e93444fba3e.

Signed-off-by: Shea Levy <shea@shealevy.com>
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"
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
haskell-hledger-interest: update to version 1.4.3
haskell-DAV: update to version 0.4.1
haskell-asn1-types: update to version 0.1.3