Fixup list.h and make small API changes to list.h
Fixup list.h and make small API changes to list.h

Remove assertions (will SEGFAULT if NULL is passed anyway) and
ty_list_remove will now init the removed head (instead of NULLing it).

And, ahem, fix the long-lasting and undetected inversion between append
and prepend (yeah yeah I know, unit-testing and all that).

Koromix/ty,Koromix/ty,Koromix/tytools,Koromix/tytools,Koromix/ty,Koromix/tytools