Changes include:
 * Remove references to old module dir from .spec
 * Use setuptools find_packages find all ansible packages

Fixes #8490

setuptools' instal_requires instead

As described by http://docs.ansible.com/intro_configuration.html#library the library supports multiple paths to load modules from. 

Currently `setup.py` treats something like `/usr/share/ansible:/my/custom/modules` as a single directory name and results in the installed modules not being on the module path. (instead they are in a directory named `/usr/share/ansible:/my/custom/modules`) 

This commit simply takes the first listed directory as the install directory for the core modules.

This reverts commit 15b89b45, reversing
changes made to 3d836a1a.

use DEFAULT_MODULE_PATH in setup.py so that there is a chance to override with ANSIBLE_LIBRARY env variable

Author: Ton Kersten <github@tonkersten.com>
Date:   Mon Apr 29 10:44:30 2013 +0200

    Fixed the installation of library directories

    When running install the `setup.py` give error

    changing mode of /usr/bin/ansible-doc to 755
    running install_data
    error: can't copy './library/utilities': doesn't exist or not a regular file
    make: *** [install] Error 1

    Debugging 'benno' came up with this patch, which works on CentOS 6.4 and
    on Ubuntu.

check path is directory
added manpage & setup
small cleanup
shut up module_formatter in utils to avoid trace print on crud files in library

If ANSIBLE_KEEP_REMOTE_FILES=1 is set as an environment file, remote files will not be deleted, which is useful only for development debugging purposes.