Fixing the issue #3292

This change fixes the issue #3292. The details were mentioned in the comments to the issue.
Fixes #3542: Removed requirement to specify `extensions` in application config
Adjustments according to comments on #3575
Include nightly HHVM builds into the build matrix
Merge pull request #3579 from DaSourcerer/travis-ci

[Travis CI] Include nightly HHVM builds into the build matrix
fix #3501 replace . when generating input ids
fixes #3473, allow precision in pgsql abstract timestamp
ignore composer.lock in applications (yii2-dev only)
fixed argument display in errorHandler
Merge branch 'master'

Conflicts:
	framework/CHANGELOG.md
Merge pull request #3575 from yiisoft/extensions-autoloading

Fixes #3542: Removed requirement to specify `extensions` in application config
fixed apidoc short description

fixes #2797
removed `@link` tags from apidoc and replaced with markdown
Basic edits

Question: Not sure about the point being made with components and
DatePicker. Please clarify if I misinterpreted.
Basic edits

Looks good!
Edited up to event handlers
guide WIP [skip ci]
Adding rotateByCopy to yii\log\FileTarget #3562
Merge pull request #3585 from pawzar/dev

Adding rotateByCopy to yii\log\FileTarget #3562
added test case to acually create cols with virtual type

verify issue #3473