Change AssetBundle.register() return type to static

Enable IDE typehints for custom AssetBundle properties (related to #2572).

Fixed typos

call hasMethod() instead of using method_exists

Fix for #2549

Fixed typo in runWithParams

Typo fixes for $user->attributes

print_r($data) should be print_r($user->attributes)

first draft of the extension generator

Raw content return for Grid DataColumn & Column

Fixes #2544: Changed `DetailView`'s `name:format:label` to `attribute:format:label` to match `GridView`

Merge branch '2524-formatter-format-file-size' of github.com:VinceG/yii2 into VinceG-2524-formatter-format-file-size

Conflicts:
	framework/CHANGELOG.md

close #2543

fixes #2220

added a missing argument

No need for it anymore.

travis seems to be really slow currently...