Bulgarian translation
Some docs on GridView
Merge pull request #3060 from avladev/lang_bg

Bulgarian translation
Looks like GridView has its own section... :)

added a hint and link
Update data-overview.md
typo
added docs about gridview filtering
Issue #3029: Implement ActiveForm and ActiveField
Update data-grid.md
add guide about filtering and sorting related columns

fixes #1581 and #3013
added not about joinWith background
allow . in input name
Merge pull request #3061 from yiisoft/grid-view-relations

add guide about filtering and sorting related columns
fixed wrong example.
updated base AR phpdoc for findOne() and findAll()
Merge pull request #3038 from mikehaertl/master

Implement ActiveForm and ActiveField
support hiding error and label tags via error(false) and label(false).
Minor refacotring of bootstrap active field and form.
#3073 added Hungarian translation
Removed unnecessary app.php file.