Add 64-bit integer type array instantiations.
Minor comments in inheritance_table.
Return a slice rather than a pointer from the skit_slice_buffered_append and its ilk.
Add skit_text_stream_new_n(size_estimate) to complement skit_text_stream_ctor_n.
Added the bag module.
Documentation fixup on bag.h
SKIT_ARRAY_ON_STACK was quite broken.  It at least compiles now.
Bugfix: Looking up the empty string on an empty trie no longer causes a segfault (null deref).