pyenv v0.4.0-20140110.1

Changes:

* pyenv: Reliably detect parent shell in `pyenv init` (yyuu/pyenv#93)
* pyenv: Import recent changes from rbenv 0.4.0
* pyenv: Import `bats` tests from rbenv 0.4.0
* python-build: Add new CPython releases candidates; 3.4.0b2
* python-build: Add ruby-build style patching feature (yyuu/pyenv#91)
* python-build: Set `RPATH` if `--enable-shared` was given
  (yyuu/pyenv#65, yyuu/pyenv#66, yyuu/pyenv#82)
* python-build: Update default setuptools version (2.0 -> 2.1)
* python-build: Update default pip version (1.4.1 -> 1.5)
* python-build: Activate friendly CPython during build if the one is not
  activated
* python-build: Fix broken install.sh
* python-build: Import recent changes from ruby-build v20131225.1
* python-build: Fix build error of CPython 2.x on the platform where the
  `gcc` is llvm-gcc.
* version-ext-compat: Removed from default plugin. Please use
  [pyenv-version-ext](https://github.com/yyuu/pyenv-version-ext)
  instead.