sub menus didn't get checked for being active.

Based off the method in ```Menu.php``` I've updated ```Nav``` so it will check if sub menus are active or not.
Improved check for active child items

Updated to avoid full tree traversal.
Also noticed ```activateItems``` didn't do anything so that's been fixed.
Update CHANGELOG.md
Added asElapsedTime function
Typo in asElapsedTime description
Call Yii::t everytime instead of passing a template variable
Typo
asElapsedTime can now take DateInterval as parameter
asElapsedTime style improvements
asElapsedTime can now take a DateInterval string as a parameter
Added support for inverted intervals (future time) and unit tests
Removed debug code, changed doc
Modified example in DataReader usage comment to reference a DB Command function which accepts a SQL string argument.
PSR-2 compliance
updated composer documentation
Merge commit '1ccad3d97db122b71b84f222807e547b86687a12' into feature/composer-docs
Merge pull request #2784 from schmunk42/feature/composer-docs

updated composer docs
fixes #2776 renamed default template folder
Merge pull request #2786 from schmunk42/feature/renamed-gii-templates

fixes #2776 renamed default template folder
Update controller.md