Site alias parameters

Prior to this patch, drush sa @dev would print @dev. Hm. To actually see the whole record, you needed to use drush sa @dev --full. While the handling of --short and --full may have been consistent from a code standpoint, it wasn't terribly useful to the end user to see @dev when that was his original input.

This patch changes drush sa such that the default output format is --full when site names are provided as parameters. When drush sa is called without parameters, the default output format is still --short.

Also, the --long output format had a bit of an odd name vis-a-vis --full. Which is longer, "long" or "full"? The "long" output is useful for passing to other scripts, so this patch also removes --long and replaces it with --pipe, which is more consistent with other drush commands.