tests improved, verify added
beforeSubmit function after global validation all fields forms
added basic greek translation
added Greek (el) as available language
removed unnecessary greek translations from core
fixed weird `#` in greek translation
Fixed typo
Merge pull request #2110 from pmoust/greek

Greek core translation
Merge branch 'tests_improved_verify' of github.com:Ragazzo/yii2 into Ragazzo-tests_improved_verify

Conflicts:
	apps/basic/tests/README.md
	apps/basic/tests/unit/models/LoginFormTest.php
Merge branch 'master' of git://github.com/yiisoft/yii2
more path fixes for apidoc command
Fixes #1782
Merge branch 'master' of git://github.com/yiisoft/yii2
Merge pull request #1958 from 6pblcb/yiiActiveForm-beforeSubmit

Transfer beforeSubmit function after global validation all fields forms
Fixes #1958: `beforeSubmit` in `yii.activeform` is now executed after validation and before form submission
doc update.