create project
ignore cache files generated by python3 and jython.
create virtualenv by actual executable name such as `python2.7` or `pypy`.
python 2.6 and older don't have "bin/python" as symlink.
so we must traverse files like "bin/python*" to obtain canonical name..
enable creating virtualenv based on "system" python.

*NOTE*
change first argument of python-virtualenv to path to the python
executable, not a prefix of python installation.
update README
update help messages
add install.sh
release 20121023
fix broken markup in README
s/an/a/g
add rbenv 0.4.x style documentation
release 20130218
Preparing for renaming project; `s/python-virtualenv/pyenv-virtualenv/g`
Update virtualenv version; 1.8.2 -> 1.8.4
update README
update README
update copyright
release v20130307
update README. add note about pyenv-virtualenvwrapper.