integrate cfgperl contents into mainline

p4raw-id: //depot/perl@5868

diff --cc Todo-5.6
index 7255363,7255363..f214ba6
--- 1/Todo-5.6
--- 2/Todo-5.6
+++ b/Todo-5.6
@@@ -13,7 -13,7 +13,6 @@@ Unicode suppor
        - a way to set default disciplines for all handle constructors:
            use open IN => ":any", OUT => ":utf8", SYS => ":utf16"
      eliminate need for "use utf8;"
--    autoload utf8_heavy.pl's swash routines in swash_init()
      autoload byte.pm when byte:: is seen by the parser
      check uv_to_utf8() calls for buffer overflow
      (see also "Locales", "Regexen", and "Miscellaneous")