- make use of traits
- short array
- better implementation of query findByPk

* master: (613 commits)
  fixed typo
  Fixes #1222: refactored jui/Widget, intorduced jui/Slider and jui/SliderInput
  Correct Nav.php comments/PHP doc to reflect BS3 dropdown support.
  Correct Nav.php comments/PHP doc to reflect BS3 dropdown support.
  Correct Nav.php comments/PHP doc to reflect BS3 dropdown support.
  Added example for dividers to bootstrap Nav
  Checkboxlist documentation fix
  Added "Using controller action to render errors"
  Fix doc
  Renamed DetailView attribute type to format
  encode email in Formatter
  Added default status code setting.
  "yii\swiftmailer\Mailer" transport setup has been advanced to support constructor arguments and plugins.
  fix rbac select statement
  Comments cleanup.
  Reverted closeButton
  Nomenclature and code realignment.
  better nginx config
  guide about using bootstrap less files
  Include Schema in new migrations by default
  ...

Conflicts:
	framework/yii/db/ActiveRecord.php
	framework/yii/db/ActiveRelation.php
	tests/unit/data/config.php

Correct Nav.php comments/PHP doc to reflect BS3 dropdown support.

Removed edited author ref.

Updated tabs

Corrected the example and doc to highlight allowed dropdown support in Bootstrap 3.

fixes #1284

Checkboxlist documentation fix

"Item" parameter keys are the values of the checkbox list,
while the values are the checkbox labels.

Fix doc

Renamed DetailView attribute "type" to "format"

for consistency with GridViews DataColumn where the same property is
also named format

avoid XSS with emails in format  "Carsten Brandt <mail@cebe.cc>"

"yii\swiftmailer\Mailer" transport setup has been advanced to support constructor arguments and plugins.

fix rbac select statement

Update Alert.php to display multiple flash messages for the session.

Cleaned up a few comments ... hope its not my OCD again... :-)

Reverted name to ```closeButton``` to be in sync with the bootstrap ```Alert``` widget.

1. Renamed closeButton to closeButtonOptions. 
2. Generate unique id for each alert box.
3. Moved parent init to the top.

Include Schema in new migrations by default

fixes #1261

worked though all the guide files adjusted structure and
added some missing does

Fixes #1222: removed Slider widget from JUI extension since it's not input widget and a wrapper doesn't really add anything