Add a comment to line for disabling "C-x C-b"
Exchange "C-x" and "C-t" for Dvorak layout
Don't disable "C-x C-b" because helm-buffers-list is bound to it
Rearrange key bindings for Helm considering exchange of C-x and C-t
Remove lines for disabling "C-c C-b" in CC mode that are no longer needed
Swap 'C-x' and 'C-t' after creating a frame

The variable keyboard-translate-table is a terminal-local variable, and
it needs to be configured for each frame.