Change modules to use credentials in my.cnf if they are available

Standardizing the apt module

Check file exists instead of relying on the exception. Leave the exception catch in, in case the file is deleted or some other issue crops up

Changing to read from a file pointer instead so that an exception is thrown if the file doesn't exist

1. Passing the module to the various functions so that they can use module.fail_json and module.exit_json methods inside.
2. Because of point 1, install and remove methods do not return anything. Instead, they use the module functions itself.
3. Move the import statement (for apt and apt_pkg) inside main function so on import error, we can use module.fail_json to print the error.

Update git module to handle branches better

This drops the branch option.  The version option is overloaded
to mean either a sha1, branch, or tag.  This also adds the option
'remote' which defaults to 'origin'.
clone() was simplified by removing the checkout operation.  That
happens later when switch_version() is called.

Added the methods get_branches(), is_remote_branch(), and
is_local_branch().  get_branches() returns an array listing all
of the branches for the git repository.  is_remote_branch() checks
whether the arguments supplied correspond to a remote branch.
Similarly, is_local_branch() checks for a local branch.

The pull() method now checks to see if it is on the desired branch.
If not, it checks out the requested branch and then does a pull.
This should keep issue #604 still fixed.

switch_version(), formerly switchver(), looks to see if it is
checking out a branch.  If a branch, it checks it out with the --track
option.  This type of checkout was in pull() before.

Updated pull, clone, and switch_version to return (rc, out, err).

Things that happen inside multiprocessing shouldn't make side effects, ergo append ansible_facts only
in playbook code.

This technically means with_items calls can't continuously add facts I guess, but I can't see anyone
ever trying that.

in them if it looks like they are not tagged, because if that is the case, then we may just
be gathering facts about them.

(make colorized playbook runs not suck on black terminals)

Standardizing the yum module

More cleanup in assemble module for module magic (tm)

Save module name and args when processing list of items.

This is necessary because daisy-chained modules will overwrite
these values.

convert sfromm's assemble to module-magic

Port command module over to new common code.  Notice that this has to subclass AnsibleModule -- this should be the only
one that has to do that.