Moved file and path related methods from StringHelper to FileHelper, renamed StringHelper byte methods not to be misused as string methods

Broken example of mail component usage

Url documentation typos

Gii crud generator broken

Update requirements.php

Removed extra parenthesis in code example

Elasticsearch debug toolbar

this panel shows all logged elasticsearch queries and allows to execute
them to see the results.

Allow Travis to be run not only for YiiSoft

Update requirements.php

Update travis to exclude packs and display verbose text

(coveralls.io still excluded)

load extensions before preloading components to have aliases set for
extensions like debug module.