dhtml_menu 7.x-1.0-alpha4

It's been a while since the Drupal 7 version of DHTML Menu has been stable enough to release a milestone, but here it is.

Most notably, this is the only version of DHTML Menu compatible with HEAD. Due to core API changes in the past few weeks or months, the older milestones are no longer functional.

Besides that, a large number of other changes have been added since the last alpha release.

New features:

- #300106: Menu items can now expand when the cursor hovers over them.
- #554030: By default, menu items now link statically while expanded, instead of collapsing.
- #555500: Cookie-based state saving is optional now, and also disabled by default as the active-trail solves the issue nicely.
- #556042: Allow toggling between blacklist/whitelist for disabling DHTML Menu.

Bugs and API compatibility:

- #356495: (thanks to dboulet): Index the menu tree to traverse it without relying on theme_menu_item_link and theme_menu_item to be called together. This ensures compatibility with Nice Menu.
- #547690: Function registry removed.
- #473356: Add upgrade path for renaming pseudo-child to clone.
- #600340 (by mgifford): Fixed absolute font sizes breaking WCAG 2.0.
- #625940: Compatibility with the new theme layer, moving off intercepts and on to preprocess functions (which finally work). hook_theme_registry_alter() is gone. Also, replaced the "require_once" with a cleaner module_load_include().

Structure:

- #478472: Settings are merged into a single system variable. The variable is set at installation; no more defaults are passed in variable_get().
- #473356: Lots of cleanup in the Javascript and PHP code, better comments.