Release coccinelle-0.2.0

** Features:
   - Remove duplicated code in disjunctions
   - Better error message when grep finds nothing relevant.  Thanks to Joe
     Perches for the suggestion.
   - added -keep_comments option for the unparsing of the transformed code
   - Option "-version" now also gives information about built-in
     Python binding support.
   - slightly faster environment manipulation in pathological cases
   - hack added to accept well-formed #define after function header

** Bugfix:
   - Proper consideration of #define macro arguments in checking for the use
     of metavariables and in computing the line numbers of complex terms
   - Better parsing of included .cocci files
   - Put included .cocci files in the right order
   - Bind position variables only once for #include
   - Fix bug in include_match that caused everything to halt when all matches
     were discarded
   - Merge unlikely/likely iso rules under a iso rule named unlikely
   - Some fixes to coccicheck rules, thanks to Andrew Lunn
   - Support groups in regular expression, thanks to Michael Stefaniuc