Keep the alias map in PHP

[cies]

Generate it as PHP code at install/init/update time..
Have it loaded as PHP (fast).
Automatically makes the mapping kind-of immutable, which either limits or focuses its use.

[rolfvandekrol]

I think it would be a great enhancement but still looking for a reliable way to do this. Few things that come into mind:

• This file is a cache, and should be treated as such. The database table is the leading source of the mapping and I think it should stay that way. That keeps the module usable, outside the context of a Kraftwagen managed site.
• The location of this file should be configured from outside the module. The only storage the module itself can reliably use is the Drupal file-system folder, which isn't a very great place for it.
• Maybe we should implement this as a Drupal caching mechanism. A bit like http://drupal.org/project/filecache, but then creating it such that arrays can actually be stored as real PHP.