Rackspace-monitoring-cli

* Add `RAXMON_` prefix to the environment variables so they don't conflict with
rackspace-monitoring-cli v0.2.3 - 2012-01-03:

* Add `RAXMON_` prefix to the environment variables so they don't conflict with
other environment variables.
[Pedro Padron]

* Add `raxmon-checks-disable` and `raxmon-checks-enable` command.

* Add `--json` option to the `raxmon-checks-test` command. This way response
can be directly piped to a file and used with `raxmon-alarms-test` command.
* Add `raxmon-alarms-test` command
* Change `rackspace-monitoring` dependency version to 0.2.1

* Add missing `target-hostname` option to the checks create, update and test
command.
* Add `raxmon-checks-test` command
* Add global `--why` and `--who` option to all the create, update and delete
commands. If `--who` is not provided it defaults to the current user username.

* Add support for commands option bash auto-completion.
* Allow user to provide credentials using environment variables
(`USERNAME`, `API_KEY`, `API_URL`)
* Allow user to pass `--marker` option to the list commands

* Initial release.