Some fix for IPython Notebook's Template

**Note**: this is a work in progress.

**Note**: this is a update to #252.

**Note**: this is related to #289, #314 and #324.

Instead of use "In" and "Out" marks for IPython Notebook this use CSS arrows (as show below).

![arrow](https://f.cloud.github.com/assets/1506457/2191489/3b21b82e-9849-11e3-9b12-5d8bc0842a71.png)