[ADD] Termite configuration and TERMINAL variable

Switching to Termite because URxvt has weird rendering issues when
resizing the font.

i3-sensible-terminal needs the TERMINAL environment variable to launch
our prefered terminal emulator with the Ctrl+d binding.

Bash and Zsh both need a hook to enable Termite to open another terminal
in the same directory with the Ctrl+Maj+t binding.

shell/.profile

@@ -4,6 +4,8 @@ PATH="$HOME/scripts:$PATH"
 # Export our favorite editor
 export EDITOR=vim
 export VISUAL=$EDITOR # Also use it when asking for a GUI
+# Export our terminal for i3-sensible-terminal
+export TERMINAL=termite
 
 # Color ls output depending on filetype with dircolors
 [ -e "/etc/DIR_COLORS" ] && DIR_COLORS="/etc/DIR_COLORS"