* use the more advanced patchelf instead of chrpath

  * use the more advanced patchelf instead of chrpath
    http://nixos.org/patchelf.html

patchelf has the ability to set a new rpath even if there was none before which chrpath seems to miss.

if a package is compiled using conda-build an initial rpath is set because of the LD_RUN_PATH: except someone unsets it in the build.sh.


patchelf advantage is: example to convert an otherwise compiled package to be used within conda.
e.g.: use a pre-compiled package and just extract in the build.sh to PREFIX.  if the originial precompiled package had no rpath set: chrpath will fail but patchelf will do the job as designed.

This is a great plus in my opinion.

P