Move common method for a CapsuleManager to trait, this would reduce the requirement to produce new CapsuleManager for other component in the future (e.g: laravel/framework#5032)

Also remove duplicate "require-dev" component (when already explicitly declare in "require").

Signed-off-by: crynobone <crynobone@gmail.com>
Avoid using fully qualified names within the code
Cleaning up a few things. Merging.
Merge pull request #5079 from GrahamCampbell/4.2-names

[4.2] Avoid Using Fully Qualified Names Within The Code
[4.2] Collection - DDRYs up the code a little more