Improved ssh_config template.

The template file for .ssh/config is much better, and shows how to create clean
ssh config files.
Improvements to vimrc + small fixes.

Several enhancements to `vimrc`:

- Current line is highlighted (especially nice with solarized)
- Tab settings are set at 4 spaces per tab, as this seems to be what I primarily
  use now.

Other than that, a few other fixes:

- `bash_profile` contains an example of how to create an alias for the LaTeX
  makefile.
- `vimrc.example` shows how to use `$HOME` to avoid having to put the full path.