Improve code for Ispell (and use "american" and "francais" as dicts)

Other things:
- Enable Show Paren mode only if `mic-paren' is not found
- Add protections for running on XEmacs without errors
- Fix latitude and longitude of Leuven
Improve doc about my key bindings
Query user when pressing `M-p' to avoid unintended printing
Remove builtin flyspell package from Leuven packages