setup: add type and default_ipv{4,6} to linux network facts

Add some docs/examples

Changes to postgresql to support defaults settings and older psycopg2

When initalizing a connection to psycopg2, in order to use the default
values, the keywords must be missing. So we use a dictionary as a kwarg
and include only the keywords that do not have an empty value on the
module parameters.

include local_nvra
change the remove behavior to pretty much NEVEr error out if the pkg is not there (or anywhere)

it is possible those folks w/o yum-utils installed but with rhn-plugin
installed but w/o any rhn-certificates will still see an error msg.
they have 3 options:
1. remove rhn-plugin
2. enable some channels w/rhn certs
3. install yum-utils

Add a basic ansible-pull man page.

Add the example playbooks/scripts to the RPM package.

Closes #841

Fix spelling of architecture for non-x86

Always load group_vars and host_vars.

Further fixes for constants following config introduction

Added an ANSIBLE_CONFIG variable to poteentially override
~/.ansible.cfg
Used os.path.expanduser against all paths that might be read in to allow
~ to be used in config files. I'd have preferred it if os.path.expanduser
took None as an argument but it doesn't.

If remote_port *is* set in the ansible config file, then it will be
interpreted as a string (at which point ssh.connect fails with an
obscure message). Most other numeric variables are handled by
the OptionsParser which takes a type variable when setting up the option -
but remote_port is not an option, so never cast to int.

It might be worth adding a type field to get_config that defaults to a string.
That could be e.g. file or int, which then casts it correctly.

Bugfix/apt repository

fixed missing module argument for mount module

Use Python 2.4 compatible syntax

A couple fixes for setup module

If ip is not found in either /sbin or /usr/sbin, this will return
an empty result.  It seems extremely unlikely that a linux system will
not have iproute2 installed

Specify full path to ip and add third argument 'show' to be explicit
about requested action.  This goes from 'ip addr' to
'/sbin/ip addr show'.

Add module common code to allow it to be easier to indicate whether arguments are mutually exclusive, required in conjunction, or whether one of a list of arguments is required.  This simplifies writing Python modules.