+ added "regs" attribute
 + fixed "pos" and "endpos" attributes
 + reset "lastindex" and "lastgroup" in scanner methods
 + removed (?P#id) syntax; the "lastindex" and "lastgroup"
   attributes are now always set
 + removed string module dependencies in sre_parse
 + better debugging support in sre_parse
 + various tweaks to build under 1.5.2