* Let libmy.c call a function in libyour.c
* Make the function in libmy.c be a constructor
* Test dlsym() with the new library

* Allow NULL this parameter in eld_elf_object_find_symbol
* Introduce eld_elf_object_is_registered
* Check that dlclose() acts on a registered library
* Check that dlopen() don't open twice the same file
* Let dlopen() actually insert the ELF in the list