HISTORY: replace n-dash to workaround pip bug

There exists a problem (maybe a bug?) in pip when using a locale like
`LC_ALL=C` (which is commonly used by CI environments and system
configuration tools such as Puppet), where the PKG-INFO file is decoded
using ascii, raising a UnicodeDecodeError when PKG-INFO contains
non-ASCII characters (such as the n-dash removed by this commit):

> Downloading/unpacking requests from https://pypi.python.org/packages/source/r/requests/requests-2.5.1.tar.gz
>   Downloading requests-2.5.1.tar.gz (443Kb): 443Kb downloaded
>   Running setup.py egg_info for package requests
>
> Exception:
> Traceback (most recent call last):
>   File "/usr/lib/python3/dist-packages/pip/basecommand.py", line 104, in main
>     status = self.run(options, args)
>   File "/usr/lib/python3/dist-packages/pip/commands/install.py", line 245, in run
>     requirement_set.prepare_files(finder, force_root_egg_info=self.bundle, bundle=self.bundle)
>   File "/usr/lib/python3/dist-packages/pip/req.py", line 1014, in prepare_files
>     req_to_install.assert_source_matches_version()
>   File "/usr/lib/python3/dist-packages/pip/req.py", line 359, in assert_source_matches_version
>     version = self.installed_version
>   File "/usr/lib/python3/dist-packages/pip/req.py", line 351, in installed_version
>     return self.pkg_info()['version']
>   File "/usr/lib/python3/dist-packages/pip/req.py", line 318, in pkg_info
>     data = self.egg_info_data('PKG-INFO')
>   File "/usr/lib/python3/dist-packages/pip/req.py", line 261, in egg_info_data
>     data = fp.read()
>   File "/usr/lib/python3.2/encodings/ascii.py", line 26, in decode
>     return codecs.ascii_decode(input, self.errors)[0]
> UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 8161: ordinal not in range(128)

I'm not able to reproduce this by installing the package directly, only by
installing another package which depends on it (via `install_requires`).

The command I used was `LC_ALL=C /usr/bin/pip-3.2 install --upgrade ocflib`,
with "pip 1.1 from /usr/lib/python3/dist-packages (python 3.2)" (which
is the packaged version for Debian 7).

Although this should probably be addressed ultimately in pip, replacing
this character in HISTORY is a pain-free and pragmatic way to help
developers and system administrators who may be stuck with old versions
of pip for many years to come.

HISTORY.rst

@@ -103,7 +103,7 @@ Release History
 - Support for connect timeouts! Timeout now accepts a tuple (connect, read) which is used to set individual connect and read timeouts.
 - Allow copying of PreparedRequests without headers/cookies.
 - Updated bundled urllib3 version.
-- Refactored settings loading from environment — new `Session.merge_environment_settings`.
+- Refactored settings loading from environment -- new `Session.merge_environment_settings`.
 - Handle socket errors in iter_content.