I'd like to propose a change that has no semantic effect on the SRFI,
just renaming of string-trim, string-trim-right and string-trim-both.

I think string-trim-both would be the most commonly-used of the three;
it should be named string-trim.

The string-trim-right procedure should be renamed because of the
left-to-right language assumption.

CURRENT		       PROPOSED
string-trim	       string-trim-head
string-trim-right      string-trim-tail
string-trim-both       string-trim

Note that in MIT Scheme (string-trim " hi ") ==> "hi".