Never pass a `char' to a ctype function. I had relied on gcc -Wall

Never pass a `char' to a ctype function. I had relied on gcc -Wall
letting me know about instances of this, but it turns out that my
ctype.h explicitly casts input values to `int' to evade the
`subscript has type char' warning, so it had been carefully not
letting me know! Found them all by compiling with a doctored
ctype.h, and hopefully fixed them all too.

[originally from svn r2927]