Merge pull request #1 from yiisoft/master

Update from original
Merge pull request #2 from yiisoft/master

Update from original
Spanish docs Theming
Fix for #6463
Fixes #6463: The Gii controller generator generates incorrect controller namespace
#4, Add new translation messages and translate that for fa-IR language.

Signed-off-by: nabi <nabikaz@gmail.com>
Merge pull request #6477 from larnu/spanish_docs

Spanish docs Theming [skip ci]
Merge pull request #6480 from NabiKAZ/fa_ir-translate-messages

[skip ci] Add new translation messages and translate that for fa-IR language.
Update mongodb-setup.sh

fixed hhvm build.
fixed namespace collision

AssetBundle can not be imported because the class already exists in this namespace.

fixes #6475
require PHP mcrypt extension

eg. used in /var/www/app/vendor/yiisoft/yii2/base/Security.php at line 465
Merge pull request #6497 from schmunk42/patch-1

require PHP mcrypt extension
Fixes #6505
use a monospace font in error details on exception page

better readability
Removed User.role from advanced application template because it was causing confusion that user could be assinged a single RBAC role and that role field is somehow tied to RBAC at all.
Fixes #6467: `ActiveForm` will scroll to the nearest visible element when the first error input is hidden
Added example about configuring theme runtime
Fixes #6514: advanced application SignupForm::signup() should not return User model if saving failed
Security best practices guide
fix  mistake small  [skip ci]