Basic documentation about RBAC

[WIP] Redis ActiveRecord

also removed composer plugin and added it to requirements
this way the plugin is recognized by composer. would not work otherwise.

setting the repo type to yii2-extension also allows us to run composer
plugin and let it handle the extensions in this package

- 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.