Fixes bugs and adds features.

• Add finalizer queues. Useful for C/C++ programs that want to replace their custom GC with Fil-C's GC, but have some semantically observable destruction or finalization mechanism.
• Make it possible to iterate the contents of a weak map.
• Build clang without a dependency on any ncurses libraries.
• Simplify the pizfix directory layout. There is no more pizfix/yolo.
• Make FILC_DUMP_ERRNOS more helpful.
• Fix a rare GC crash due to a race in the weak reference load barrier. Only affected code that used weak references (only the Fil-C tests do that, to my knowledge).
• Fix handling of bad FDs to dup/dup2/fcntl.
• Improve version script handling of wildcards.
• Make select/pselect access fd_sets that are smaller (or larger) than FD_SETSIZE. Make the safety checking based nfds.
• Make select/pselect return EINVAL for negative nfds values.
• Make zsys_close capable of handling absurd fd values without running out of memory.