=head1 Incompatible Changes
+=head2 Unicode interpretation of \w, \d, \s, and the POSIX character classes redefined.
+
+Previous versions of Perl tried to map POSIX style character class definitions onto
+Unicode property names so that patterns would "dwim" when matches were made against latin-1 or
+unicode strings. This proved to be a mistake, breaking character class negation, causing
+forward compatibility problems (as Unicode keeps updating their property definitions and adding
+new characters), and other problems.
+
+Therefore we have now defined a new set of artificial "unicode" property names which will be
+used to do unicode matching of patterns using POSIX style character classes and perl short-form
+escape character classes like \w and \d.
+
+The key change here is that \d will no longer match every digit in the unicode standard
+(there are thousands) nor will \w match every word character in the standard, instead they
+will match precisely their POSIX or Perl definition.
+
+Those needing to match based on Unicode properties can continue to do so by using the \p{} syntax
+to match whichever property they like, including the new artificial definitions.
+
+B<NOTE:> This is a backwards incompatible no-warning change in behaviour. If you are upgrading
+and you process large volumes of text look for POSIX and Perl style character classes and
+change them to the relevent property name (by removing the word 'Posix' from the current name).
+
+The following table maps the POSIX character class names, the escapes and the old and new
+Unicode property mappings:
+
+ POSIX Esc Class New-Property ! Old-Property
+ ----------------------------------------------+-------------
+ alnum [0-9A-Za-z] IsPosixAlnum ! IsAlnum
+ alpha [A-Za-z] IsPosixAlpha ! IsAlpha
+ ascii [\000-\177] IsASCII = IsASCII
+ blank [\011 ] IsPosixBlank !
+ cntrl [\0-\37\177] IsPosixCntrl ! IsCntrl
+ digit \d [0-9] IsPosixDigit ! IsDigit
+ graph [!-~] IsPosixGraph ! IsGraph
+ lower [a-z] IsPosixLower ! IsLower
+ print [ -~] IsPosixPrint ! IsPrint
+ punct [!-/:-@[-`{-~] IsPosixPunct ! IsPunct
+ space [\11-\15 ] IsPosixSpace ! IsSpace
+ \s [\11\12\14\15 ] IsPerlSpace ! IsSpacePerl
+ upper [A-Z] IsPosixUpper ! IsUpper
+ word \w [0-9A-Z_a-z] IsPerlWord ! IsWord
+ xdigit [0-9A-Fa-f] IsXDigit = IsXDigit
+
+If you wish to build perl with the old mapping you may do so by setting
+
+ #define PERL_LEGACY_UNICODE_CHARCLASS_MAPPINGS 1
+
+in regcomp.h, and then setting
+
+ PERL_TEST_LEGACY_POSIX_CC
+
+to true your enviornment when testing.
+
+
=head2 In @INC, move ARCHLIB and PRIVLIB after the current version's site_perl and vendor_perl.
=head2 Switch statement changes
=head2 Add a pluggable hook in op_free()
+
+
+