add dirty trick for readline import on OSX...
add dirty trick for readline import on OSX
also made the libedit warning extremely loud, so people don't miss it.
We still get reports of people never having noticed the warning, and
getting confused when readline is broken on OSX.
The reason for the dirty trick:
pip installs to site-packages by default, but site-packages dirs always
come *after* lib-dynload (and extras, etc.), which is where the system
readline is installed.
That means that a non-setuptools install (pip or setup.py install) *cannot*
override any package that ships with OSX, including:
numpy, readline, twisted, pyobjc
without installing to a non-standard path (not even user site-packages via `--user`).
The method for the dirty trick:
1. remove lib-dynload from sys.path before trying to import readline the first time
2. after import, restore lib-dynload to its place in sys.path
3. if import failed without lib-dynload, try it one more time
