rpm build: Used --prefix=%{_prefix} when running setup.py install

Without --prefix rpm build fails on OpenSUSE because default prefix is
/usr/local

This is how it breaks on OpenSUSE:
[   18s] RPM build errors:
[   18s]     File not found by glob:
/home/abuild/rpmbuild/BUILDROOT/ansible-1.4.1-11.1.x86_64/usr/lib/python2.7/site-packages/ansible*
[   18s]     File not found by glob:
/home/abuild/rpmbuild/BUILDROOT/ansible-1.4.1-11.1.x86_64/usr/bin/ansible*
[   18s]     File not found by glob:
/home/abuild/rpmbuild/BUILDROOT/ansible-1.4.1-11.1.x86_64/usr/share/man/man3/ansible.*
[   18s]     Bad exit status from /var/tmp/rpm-tmp.GdoWaS (%doc)
[   18s]     Installed (but unpackaged) file(s) found:
[   18s]    /usr/local/bin/ansible
[   18s]    /usr/local/bin/ansible-doc
[   18s]    /usr/local/bin/ansible-playbook
Removed docs/man/man3/*.3 and PKG-INFO from rpm spec

man3 pages and PKG-INFO file don't exist in 1.4.1 tree, which causes
rpm  build to fail. This change removes above files from the spec, which
should fix build failure.
Fixed rpm build on OpenSUSE

Here is the failure:
[23s] ansible-1.4.1-15.1.noarch.rpm: directories not owned by a
package:
[   23s]  - /usr/share/ansible/cloud
[   23s]  - /usr/share/ansible/commands
[   23s]  - /usr/share/ansible/database
[   23s]  - /usr/share/ansible/files
[   23s]  - /usr/share/ansible/internal
[   23s]  - /usr/share/ansible/inventory
[   23s]  - /usr/share/ansible/messaging
[   23s]  - /usr/share/ansible/monitoring
[   23s]  - /usr/share/ansible/net_infrastructure
[   23s]  - /usr/share/ansible/network
[   23s]  - /usr/share/ansible/notification
[   23s]  - /usr/share/ansible/packaging
[   23s]  - /usr/share/ansible/source_control
[   23s]  - /usr/share/ansible/system
[   23s]  - /usr/share/ansible/utilities
[   23s]  - /usr/share/ansible/web_infrastructure

This change adds these dirs to %files section in the spec
Fixed missing build dependency for Ubuntu

python-support was missing in debian/control, which breaks Ubuntu
package builds:
[   52s] make: dh_pysupport: Command not found
[   52s] make: *** [binary-install-python/ansible] Error 127