Finally rid of the strcasestr warning

There is something seriously messed up in these files though
(like the declaration in xtag.h do not match the definition in xtag.c!)

(which includes config.h which defines the platform feature macros)
Also remember stdio, string and stdlib are included implicitly

services_discovery.c: Patch by Alexander Gall <gall # switch.ch>, avoid crashing on systems that don't handle NULL string in ..printf.

cosmetics.

Fix some segfaults by disabling functions.
Slower, faster are on the side of the slider now.

 - Don't use the .ui, do all by hand :)
 - Use a ControlWidgets to design all the controls, and implement the functions
 - Change a bit the advanced widget, that must be integrated in the
   controlsWidget
There is a lot of Not Yet Implemented, so feel free to add some.

Redesign the label & edits placement to resize the dialog