Fixes #5190: Correctly strips duplicate (type)/ from simplecache URL
Fixes 5013: Uses menu system for "Register" and "Lost password" links.
Fixes #5342: Login completes if [login, user] event redirects
Added target_guid and related functionalities to river.
Deprecates add_to_river in favor of elgg_create_river_item.
added tests for elgg_create_river_item()
Added target_guid to database schema.
Prefetches target entity for river.
Replaced add_to_river() with elgg_create_river_item().
Adds better validation for river parameters.
updated changes file for the 1.8.15 release
Uses _elgg_retrieve_cached_entity() instead of retrieve_cached_entity().
Updated commit for messages_get_unread function

replaces https://github.com/Elgg/Elgg/pull/5396#issuecomment-16930955

I don't know the prefered process to edit a submitted commit (directly on the website), please tell me if there's a better way than adding a new commit ?

Thanks
Merge pull request #5394 from juho-jaakkola/target_guid

Adds target guid to river
Fixes #5345: Embed media in CKEditor textareas will insert content at last caret position
updated comments for inserting html into ckeditor for embed plugin
cleaned up caching code - deprecated several functions
Merge pull request #5192 from mrclay/5190-sc-url

Fixes #5190: Correctly strips duplicate (type)/ from simplecache URL
made php's get simple cache function match js one
Rewrote PHP coding standard w/r/t PSR-2