Update .gitignore
Fixes #4636: Added `yii\web\Response::setDownloadHeaders()`
Fixes #4501: Renamed the constant `YII_PATH` to `YII2_PATH`
added bower.json for yii2-framework. [skip ci]
updated ignore. [skip ci]
adjust bower.json further [skip ci]
do not export mailer in BaseMailerTest message

fixes test break in HHVM due to export of a closure
fixed some inconsistnecies in HHVM tests

exclude parts that have different default values
more on HHVM compatibility
skip application tests on HHVM
HHVM version ouput has changed
fixed HHVM test break
Merge branch 'master' into codeception-test-adjustments

Conflicts:
	.travis.yml