add handler property to yii\web\Session
Added to the basic app, fixed config, added to core commands.
fixture controller improved
added .travis.yml to basic app

issue #1744
Reverted config change

change was made in 0d263a12a9dbf3f0cb8569db40f0581dc002285b

issue #1744
alias fixed
Merge pull request #1759 from Ragazzo/fixtures_controller_improvements

Added to the basic app, fixed config, added to core commands.
Basic app: DB configuration in separated file
code style fixes
moved dev requirements to require-dev in app composer.json

fixes #1736
Merge pull request #1761 from lucianobaraglia/master

Basic app: DB configuration in separated file
simpler implementation of the handler property in yii\web\Session
CHANGELOG maintainance and code style
applied fixture command docs from #1762

closes #1762
updated apps/basic/.travis.yml
Redundant event's instanceof check

And some docs punctuation.
Merge pull request #1769 from crtlib/patch-3

Redundant event's instanceof check and some docs punctuation
fix template guide, twig section
updated docs of Event
allow class level trigger call on Event subclasses

e.g. UserEvent::trigger('event', 'class');
should result in a UserEvent to be passed to the handlers instead of
a base\Event.