generic and specific parameters separated in help output

generic and specific parameters separated in help output

Play with array_diff_key to output Maintenance class parameters separately
from the script specific parameters which are shown below. Will hopefully
make easier to find out in the list of supported parameters.

Example usage with maintenance/attachLatest.php:

$ php maintenance/attachLatest.php --help

Fix page_latest entries in the page table

Usage: php attachLatest.php [--conf|--dbpass|--dbuser|--fix|--globals|--help|--memory-limit|--quiet|--server|--wiki]

Generic maintenance parameters:
    --help: Display this help message
    --quiet: Whether to supress non-error output
    --conf: Location of LocalSettings.php, if not default
    --wiki: For specifying the wiki ID
    --globals: Output globals at the end of processing for debugging
    --memory-limit: Set a specific memory limit for the script, "max"
        for no limit or "default" to avoid changing it
    --server: The protocol and server name to use in URLs, e.g.
        http://en.wikipedia.org. This is sometimes necessary because server name
        detection may fail in command line scripts.

Script dependant parameters:
    --dbuser: The DB user to use for this script
    --dbpass: The password to use for this script

Script specific parameters:
    --fix: Actually fix the entries, will dry run otherwise

$

Commit best viewed by ignoring white spaces:
 svn diff -x -bu maintenance/Maintenance.php