Port Qt4 connections and fix warnings
Clang warning: Branch condition evaluates to a garbage value [clang-analyzer- core.uninitialized.Branch] Variable "ok" may be uninitialized in second condition
Build warnings:
- KMessageBox::sorry() is deprecated, use KMessageBox::error() instead
- QStyle::PM_DefaultLayoutSpacing is deprecated, use QStyle::PM_LayoutVerticalSpacing instead
- headers KAuthAction, KAuthExecuteJob, KAuthHelperSupport and etc. are deprecated, use headers from KAuth/ dir instead