Improved errors appearance

### Before:

![1 gif](https://cloud.githubusercontent.com/assets/1045476/5514633/5314c788-8843-11e4-9610-70a6307f14cb.gif)

### After:

![2](https://cloud.githubusercontent.com/assets/1045476/5514635/5663c88a-8843-11e4-9e80-4c98e11cc41e.gif)

The latter feels more like vanilla vim.