Emacs: Removes "company-inf-python" and don't create another buffer at
startup anymore.
Emacs: Disable company mode on eshell
Emacs: Adjustments on evil mode

- <leader>s now, saves and goes to normal mode;
- <leader>a goes to the first non-black character of the line;
- <leader>e goes to the end of line;
- <leader>g goes to previous buffer;
- <leader>h goes to next buffer;
- Setup a workaround to echo the <leader> character itself.