Since Nix 1.4, expressions like "${path}/blabla" always evaluate to a
string rather than a path. However, findLaTeXIncludes depended on the
old (weird) behaviour, leading to errors like:
error: string `/nix/store/4c32q75in74m1148anlzdhb8jpppab0s-bla/IEEEtran.cls' cannot refer to other paths
So use path concatenation instead.
Merge conflicts:
* unzip (almost trivial)
* dvswitch (trivial)
* gmp (copied result of `git merge`)
The last item introduced gmp-5.0.3, thus full rebuild.
+ensureDir->mkdir -p in TeX packages was catched by git but not svn.
svn path=/nixpkgs/branches/stdenv-updates/; revision=32091