bashrc: add hostname on prompt.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
bashrc: output hostname in light blue.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>
tmux: add tmux.conf dotfile stubs.

Signed-off-by: Emmanuel Roullit <emmanuel.roullit@gmail.com>