Improves lineinfile's error checking

Line in file would raise a TypeError exception if
the 'line' key was in params, but its value was None.
Makes pervious lineinfile fix more explicit
Introduce open-iscsi module to manage targets on the initiator.
Add crypt scheme to htpasswd params
Add option to specify the MySQL server port
Added collection of user's env
Signed-off-by: Brian Coca <briancoca+dev@gmail.com>
Add support to Boto library < 2.5.0
Update instance_profile_name message
add jail module, based on lxc and chroot connexion plugin
add inventory script for listing jails on *bsd
using AIX 'csum' command for generating MD5 checksums
Fix some "make pep8" errors in the digital_ocean module.
Fix an example with a yaml syntax error.
Add a new unique_name param to the digital_ocean module for idempotence.

As it stands now, it is difficult to write idempotent tasks for digital
ocean droplets.  Digital ocean assigns new nodes a random id when they
are provisioned and that id is the only key that can be used to identify
it in subsequent runs of that play.

The workflow previously involved manual intervention:

- write a play defining a new node with no specified id
- run it, collect the randomly assigned id by hand
- modify the play to add the id by hand so future runs don't create
  duplicate nodes
- perform future re-runs that check if the node exists (by its id)
  - if it does exist then do nothing.
  - if it does not exist, then create it and return a *new random id*
  - collect the new random id by hand, modify the playbook file, and
    start all over.

Its a huge pain.

The modifications in this commit allow you to use the 'hostname' as a
primary key for idempotence with digital ocean.  By default, digital
ocean will let you create as many hosts with the same hostname as you
like.  Here, we provide an option to constrain the user to using only
unique hostnames.

The workflow will now look like:

- write a play defining a new node with a specified hostname and
  "unique_name: true""
- run it, create the new node and move on.
- re-run it, notice that a node with that hostname is already created
  and move on.
Add option for DNS nameservers to quantum_subnet module
htpasswd docs: add notes about depending on python-passlib
Module to manage kernel modules
Add Python 2.4 support to modprobe module
dest in s3 module does not work with ~username notation for home directories.  Wrapped dest definition in os.path.expanduser() which will return the expanded path in case of successful tilde expansion and otherwise the original value
Added md5 as a jinja filter - returns hex digest of input