[development] Module backwards compatibility

[Earnie Boyd]

Quoting Larry Garfield <larry at garfieldtech.com>:

> The API changes from one version to another are not simply removing one
> function and adding another.  The data structures change, because they have
> to for some features.
>

One of the 4.6.x, 4.7.x and 5.x modules is named legacy[1] to provide 
supposed backward compatibility[2].  I do not know if it works, haven't 
tried it.  Is is sticking around for 6.x?  Should it go away?  I've 
never seen it mentioned in this or the support list as a viable 
solution. I don't find it listed[3] so maybe it is gone already.

[1] http://drupal.org/handbook/modules/legacy
[2] http://api.drupal.org/api/file/modules/legacy/legacy.module/5
    http://api.drupal.org/api/file/modules/legacy.module/4.7
[3] http://api.drupal.org/?q=api/file/modules/legacy/legacy.module/6

Earnie