Fixed support for Multiple E-mail Addresses after #2501533: Make multiple_email_load_addresses() return value as documented.

Fixes:

#2333927: User reference misses fields
#2269537: Show Pictures in Merge Data

Fixed #1643358: database errors.
Fixed #2301161: Expose entities found in usermerge_get_authorable_entities in merge data form.

Fixes #2269533: Notices on "Review Account Data" screen.

Fixes #2254479: Proper invocation of hook_usermerge_accounts_alter().

This release introduces a couple of important changes:

• the merged account is saved before the old one is deleted or blocked. This prevents properties whose existence is linked to that of the user account (such as field collections) to be deleted before their ownership is passed onto the merged account.
• API hooks are now invoked using custom functions, which replace module_invoke_all() and module_implements). This fixes an issue where hook implementations weren't properly invoked, randomly breaking the module's functionality.

This development version may contain experimental or untested features (particularly in the includes directory) that aren't ready for production sites.