Make search name column width dynamic

Before:

    $ pip search pytest | egrep 'bytecode|template|cache|cpp'
    pytest-cpp                - Use pytest's runner to discover and execute C++ tests
    pytest-cache              - pytest plugin with mechanisms for caching across test runs
    python_boilerplate_template - PasteScript template for initializing a new buildout/pytest/travis/setuptools-enabled Python project
    pytest-remove-stale-bytecode - py.test plugin to remove stale byte code files.

After:

    $ pip search pytest | egrep 'bytecode|template|cache|cpp'
    pytest-cpp                       - Use pytest's runner to discover and execute C++ tests
    pytest-cache                     - pytest plugin with mechanisms for caching across test runs
    python_boilerplate_template      - PasteScript template for initializing a new buildout/pytest/travis/setuptools-enabled Python project
    pytest-remove-stale-bytecode     - py.test plugin to remove stale byte code files.

This might help with https://github.com/pypa/pip/pull/1415 (although it might also cause a merge conflict).