Make Drush call command hooks more consistently.

Here's a patch. The code was practically made to do this. It's much less confusing for folks if they can count on hooks firing uniformly. (Note: the two new calls to drush_log are nice for testing this, but perhaps should be removed before committing it to reduce noise in debug mode. Then again, most commands only implement one callback hook; maybe it's okay to keep these here.)

This was really easy to test; all I needed to do was add a callback to the unit-invoke test. Without this patch, hooks are not supported, and the test fails.

Adding this test exposed another issue. Prior to this patch, the command hook was based on the callback name, not the command name, in instances where the callback hooks were supported. This isn't right in the general case, though, where the command hooks are supported regardless of the naming conventions used by the callback function. For example, in the case of unit-invoke, when I added a callback that changed the primary function to drush_unit_invoke_primary, that changed the command hook from unit_invoke to unit_invoke_primary. I therefore changed the code in command.inc to preserve the command hook, so that the addition of a callback function would not change the name of the command hook functions.

This is a change from Drush 5, and will affect any command that depends on this somewhat odd behavior. The only thing I found so far that does depend on this is the completion unit tests. The easy thing to do in instances like this is to set the command hook in the command record. The command hook is what is used to generate the function names used in the command hooks, so setting the command hook for all of the completion commands to the same value restored the previous behavior it depended on.

For details, see http://drupalcode.org/project/drush.git/commitdiff/f3963f0

I made two adjustments to fix this. First, the 'normal' command hook is no longer called if a 'callback' command hook is supplied. This should be sufficient to fix the reported problem. Second, I added an 'invoke hooks' item that may be set FALSE to avoid all command hooks when a 'callback' is specified. This can be used if a function is still experiencing filename collisions with the command hooks.

Fixed typo. Thanks.