Database: fixed (?) missing columns for normalizeRow [Closes #1198]

I don't know why this bug exists and I don't know why this fix works :-(
Mail: SmtpMailer uses HTTP_HOST instead of SERVER_NAME [Closes #1184]
Mail: getRandomId() relies on HTTP_HOST and php_uname (for CLI). HTTP_HOST is checked.
Http: supports for IPv6 address in HTTP_HOST [Closes #1185]
Http\Response: enabled custom status codes
netteForms.js: declared variable `values`
netteForms.js: getAttribute() returns empty string in old browser when the attribute does not exist [Closes #1193]
Partially reverts "LimitedScope::load allows load script once [Closes #321]", issue #321 was solved by 917b3819;

API is the same, just include_once is replaced with require (without _once)
Environment: DI container class is named EnvironmentContainer instead of SystemContainer

It prevents "Compile Error: Cannot redeclare class SystemContainer" when another container is later created by Configurator, and shows correct error "SystemContainer has already been created automatically by Nette\Environment"
Nette\Framework: added constant VERSION_ID
Released version 2.0.12