Add Script Flags to make code more usable.

[dalgibbard]

Examples requiring adding to code:

• "-a|--auto" - Apply patches automatically (Reboot not automatic though- see below)
• "-r|--reboot" - Automatically Reboot if/when required post-patching.
• "-q|--quiet" - Remove Verbose Output.
• "-l|--list" - List required Patches which are yet to be applied.

Therefore, someone running the following could patch a host hands-free:

./patcher.py -a -r

Or, Someone wanting to be notified of newly available, not yet applied patches could put this into Cron:

# Notify at 8am each day of pending patches.
0 8 * * * /path/to/patcher.py -l

[dalgibbard]

This also implicitly adds a requirement for "-h|--help" for displaying usage.

[dalgibbard]

The following flags are implemented in commit: fbb15f65ec4f179fe8d4d5a6b723e96649514630

-a  => Auto Install Patches
-e  => Exclude patches defined in a (pythonic) list
-r  => Allow for automatic reboot of node where required.
-l  => Just list available patches and take no further action.
-v  => Display script version
-h  => Display usage

Will consider adding "-q" for less verbosity later, but I don't see an enormous need for it at the moment. Will close this and leave it in the README as a reminder.