hook_block_info_alter() Does Not Allow Blocks to Be Repositioned

Problem/Motivation

We should be able to reposition, enable, and create blocks using hook_block_info_alter(), but it is only invoked in _block_rehash, and for some reason _block_rehash does the exact opposite right below a comment stating intent to this effect, and in fact deletes the inactive block that we are trying to reposition.

Proposed resolution

Make the code not blatantly incorrect.

Remaining tasks

• Merge the patch.
• Perhaps remove the delete query at the end of the function, since it seems to serve no purpose whatsoever.

User interface changes

When a module that implements hook_block_info_alter() is active, the blocks it did not accidentally delete will be available for the user to configure.

API changes

Calling _block_rehash is less likely to delete blocks that you did not want deleted.