Change tabulation width from 4 to 8
Add and fix auto-fill mode in programming modes
Enable gtags-mode in C languages
Remove obsolete compile-colors and buffer-name

I no longer use both of these commands, mainly because I no longer use
eshell to work.
Anyway, the compile-colors still produces errors when running a grep in
a frame, so let's remove it.
Remove tool-bar-mode and scroll-bar-mode

The tool-bar-mode and scroll-bar-mode were not correctly removed when
running with an emacs compiled with frames.
I can no longer see the modes now.
Stop entering debugger on errors

It's probably better to keep this commented because it's true that
sometimes it's nice to have the debugger. But most of the time I don't
won't to have a new window pop open whenever there is the slightest
warning.