[S32]: Remove 'm' (complex) modifier from sprintf, in hopes of a

more unified approach to formatted printing for Perl 6 (e.g.,
what about formatting Rats?).

The idea here is to take a minimalist approach to 'sprintf' --
supplying the conversions that people are familiar with from
other languages and libraries, but be cautious about layering
on new "ad-hoc"-ish options until we have a better plan for
handling them all.  This is addressed further in
#13 .

S32-setting-library/Str.pod

@@ -446,25 +446,21 @@ Perl 5 (non-)compatibility:
  n   produces a runtime exception
  p   produces a runtime exception
 
-Modifiers change the meaning of format directives. The most important being
-support for complex numbers (a basic type in Perl). Here are all of the
-modifiers and what they modify:
+Modifiers change the meaning of format directives.  At the moment 
+these are recognized primarily for compatibility with C<printf>
+from other languages (notably C and Perl 5), but their exact semantics
+are still conjectural.
 
  h interpret integer as native "short" (typically int16)
  l interpret integer as native "long" (typically int32 or int64)
  ll interpret integer as native "long long" (typically int64)
  L interpret integer as native "long long" (typically uint64)
  q interpret integer as native "quads" (typically int64 or larger)
- m interpret value as a complex number
-
-The C<m> modifier works with C<d,u,o,x,F,E,G,X,E> and C<G> format
-directives, and the directive applies to both the real and imaginary
-parts of the complex number.
 
 Examples:
 
- sprintf "%ld a big number, %lld a bigger number, %mf complexity\n",
-    4294967295, 4294967296, 1+2i);
+ sprintf "%ld a big number, %lld a bigger number\n",
+    4294967295, 4294967296;
 
 =item fmt