Initial commit of the installer script and associated instructions.
Added install commands for Ubuntu/Debian.

 - Fixed the install command to include `sudo` and added a boldface warning about blindly installing the script.
Added prompts for the Username and API key.

 * Silenced apt-get update.
 * Set the checks for the distro to be general string matches instead of exact string matches.
Fixed the install command for the Rackspace Monitoring script.

Using "curl url | bash" does not respect the `read` lines, and using "bash <(curl url)" does not allow for elevating the privilege on bash ("sudo bash <(curl url)" fails).
Added Debian 6 support to the Rax Monitoring Agent install script.
Added support for CentOS, Fedora, and RedHat to the Rax Agent.
Fixed CentOS issues in the install script.
Added support for Red Hat 7 and CentOS 7 to the monotoring agent script.
Removed unnecessary `sudo`s from the monitoring agent install script.
Merge pull request #2 from amussey/rax-mon-agent-installer

Rackspace Monitoring Agent installer script.