Fix descriptions on X11 related packages
Remove preprocessor checks from TestShell.h

* This is a header used by several parts of the code which should not
need to know about ELF symbol overriding and the fact that it is
optional.
* When the define is set, the methods will not be defined, but they
shouldn't be called, either
* This makes sure the memory layout of the class stays the same with the
define set or unset, and users can rely on it.

Fixes UnitTester on gcc2.