Some final (I hope) updates:
- adopt Noah's configure code for -Wno-declaration-after-statement
- remove some code that proved to be dead, replaced by comments and
asserts
- add header comments for the public entry points
- move definition of buffer lengths to public header and comment them
- comment some assumptions that might otherwise be overlooked
- simplify some of the fixed-point optimizations slightly
- clarify some comments
- change _buf variants to return the string length, just because they can
--
Andrew (irc:RhodiumToad)
