Range tables

[Ben Wing]

In the process of trying to use range tables in mods to patcher I found what
I thought was a bug in their implementation.  Turns out it was lack of
understanding -- range tables as currently (previously) implemented always
used closed-closed ranges, which is incorrect for ranges of buffer
positions, which are closed-open.  So I went and added a type argument to
make-range-table that lets you control the interpretation of the ranges, and
I want to make the default closed-open.  There is no code anywhere in the
packages that uses range tables, and the one place in Lisp code that
currently uses them (font-lock) uses them *WRONG* since it also assumes
closed-open ranges!  What do people think about changing the default
behavior like this?