Add `tput` to the Anaconda's default blacklist in order to prevent pyenv
from creating the shim script for it.

Anaconda 5.0.0 contains some executables which are part of the base
system. Many of these executables did not exist in the last major
version of Anaconda (`4.4.0`), and the existence of pyenv's shim
scripts for these executables in `5.0.0` can cause to conceal those
executables in the user's base system; for the details, please see the
discussion with @yyuu at #992.

This commit resolves a coloured output error when running a terminal
command which uses `tput`. This error occurs when multiple Python
versions are installed alongside `anaconda2-5.0.0` or `anaconda3-5.0.0`
and neither of those two Anaconda versions is selected by pyenv.

`pip -v install foobar` or `pip -q install foobar` did not trigger a rehash before. Now it should have the same behaviour as `pip install foobar`.

The performance issue must be caused by too many I/O requests to
`conda.txt` from fgrep. This inline expansion should work to reduce # of
read to the `conda.txt`.

original performance:

```
% git rev-parse HEAD
4f76be6a12
% time bash -c 'pyenv rehash'
bash -c 'pyenv rehash'  0.05s user 0.02s system 76% cpu 0.089 total
```

previous commit: ==> 4x slower than original

```
% git rev-parse HEAD
4469d51ef7
% time bash -c 'pyenv rehash'
bash -c 'pyenv rehash'  0.06s user 0.03s system 25% cpu 0.358 total
```

with this workaround: ==> almost same as original

```
% git rev-parse HEAD
3ffe91bdbc
% time bash -c 'pyenv rehash'
bash -c 'pyenv rehash'  0.05s user 0.00s system 68% cpu 0.082 total
```

With this, we'd be able to remove a hook script for `pyenv which`
eventually.

Basically I'd like to use system pakcage for `xz` command as much as
possible.

Fixes https://github.com/yyuu/pyenv/issues/367