BAC-156:
* get rid of "devbox" default database
* redirect to $wgDevboxDefaultWikiDomain when no domain is provided
BAC-156:
* add $wgDevboxSkipWikiFactoryVariables that will disable wiki-specific settings loaded via WikiFactory
* small cleanup of Special_DevBoxPanel and devbox LocalSettings
Merge pull request #574 from Wikia/BAC-156

Get rid of "devbox" database and create a way to run the code without wiki specific settings