New features for users:
- Integration with TCL modules and dotkit
  - spack use/unuse, spcak load/unload
- Works with Python 2.6 (as well as 2.7 like before)
- 24 new packages:
  adept-utils  extrae      libmonitor  ompss    papi        scorep
  clang        hwloc       llvm        opari2   paraver     sqlite
  cube         libarchive  llvm-lld    openssl  postgresql  wx
  dtcmp        libcircle   lwgrp       otf2     scalasca    wxpropgrid

New features for packagers and developers:
- Per-version URLs
- Compiler-dependent C++11 flag
- CMAKE_PREFIX_PATH and PKG_CONFIG_PATH now set before install()
- Improved spec design, more stability
- New commands:
  - spack pkg
  - spack cd
  - spack location