- actually enabled charset anchors in the engine (still not

used by the code generator)

- changed max repeat value in engine (to match earlier array fix)

- added experimental "which part matched?" mechanism to sre; see
  http://hem.passagen.se/eff/2000_07_01_bot-archive.htm#416954
  or python-dev for details.

Lib/sre_constants.py

@@ -33,6 +33,7 @@ GROUP = "group"
 GROUP_IGNORE = "group_ignore"
 IN = "in"
 IN_IGNORE = "in_ignore"
+INDEX = "index"
 INFO = "info"
 JUMP = "jump"
 LITERAL = "literal"
@@ -90,6 +91,7 @@ OPCODES = [
     CATEGORY,
     CHARSET,
     GROUP, GROUP_IGNORE,
+    INDEX,
     IN, IN_IGNORE,
     INFO,
     JUMP,