added asSize method to format file size #2524
Merge branch 'master' of git://github.com/yiisoft/yii2 into 2524-formatter-format-file-size
no need for as number #2524
#2524 updated as size method to include translation and verbose mode
updated formatting
updated code according to code style and removed unused property
updated changelog
Merge branch '2524-formatter-format-file-size' of github.com:VinceG/yii2 into VinceG-2524-formatter-format-file-size

Conflicts:
	framework/CHANGELOG.md
Adjusted code formatting