Returns the data which have been validated

Lets continue the process with only validated datas

Move commit on 4.2 branche : https://github.com/laravel/framework/pull/4833
Rename method in passed
Use negated filter for reject
Return trashed models with morphTo() if told so on non-eager queries (fixes #4870)
add Passes method to run validation
Add ability to add and remove observable events
Additional tests and bugfix
[4.2] Fix groupBy() bug

As described here
https://github.com/laravel/framework/pull/4276#issuecomment-45563986 by
@JosephSilber
Uncomment out test
4.2-fix-associate-on-morphTo
New Validator rules format + tests. (#5127)
Validator array rule extraction order
Removed extra new line
Fixed routing docblocks
Fixed workbench throws docblocks
Small tweaks for methods that called often during application boot. For default Laravel application with 100 routes these tweaks eliminates hundreds of unnecessary calls. As a result execution time reduces significantly.
I got more than 15% however independent measurement would be highly appreciated.
Remove double if
remove double if
Merge pull request #5143 from GrahamCampbell/4.2-routing

[4.2] Minor CS Fixes To Routing
Merge pull request #5146 from lucasmichot/4.2-performances

[4.2] Database : remove double if