pyenv 0.4.0-20140516

Changes:

* pyenv: Prefer gawk over awk if both are available.
* python-build: Add new PyPy release; pypy-2.3, pypy-2.3-src
* python-build: Add new Anaconda release; anaconda-1.9.2
* python-build: Add new Miniconda releases; miniconda-3.3.0, minoconda-3.4.2, miniconda3-3.3.0, miniconda3-3.4.2
* python-build: Add new Stackless releases; stackless-2.7.3, stackless-2.7.4, stackless-2.7.5, stackless-2.7.6, stackless-3.2.5, stackless-3.3.5
* python-build: Add IronPython versions (setuptools and pip will work); ironpython-2.7.4, ironpython-dev
* python-build: Add new Jython beta release; jython-2.7-beta2
* python-build: Update default setuptools version (3.4.1 -> 3.6)
* python-build: Update default pip version (1.5.4 -> 1.5.5)
* python-build: Update GNU Readline (6.2 -> 6.3)
* python-build: Import recent changes from ruby-build v20140420