Release coccinelle-0.2.4rc3

Release coccinelle-0.2.4rc3

** Language:
   - scripts now have names and can declare metavariables that are seen by
     SmPL as identifier metavariables, see demos/{python,ocaml}tococci.cocci
   - declaration (match variable declarations) and field (match structure
     field declarations) metavariables
   - matching of array initializations and of enum declarations

** Features:
   - compatability with Python 2.7.  Thanks to Richard W.M. Jones for pointing
     out the problem
   - python and ocaml string representations of parameter lists and expression
     lists
   - try simpler patterns on glimpse failure
   - graceful and immediate failure when a virtual rule is defined on the
     command line, but not in the rule
   - spatch returns -1 when a virtual rule is requested that is not supported
   - no transformation when using * with the option -no_show_diff

** Bugfix:
   - detect used after metavariables in simple statement metavariable match
   - allow inheriting position variables over rules that make transformations
     but depend on virtual rules that are not defined on the command line
   - treat top-level tokens in decl visitor.  Thanks to Peter Tummeltshammer
     for noticing a resulting problem.
   - improve typing of the result of an assignment expression
   - eliminate some recursive calls in C code parsing to avoid tack overflows
   - better pretty printing of #define when the whole line is removed
   - better pretty printing of asm code containing
     "::[input]"r"(&coherence_data[i])"
   - allow pretty printing of C code with nameless bit fields
   - avoid adding an error message to standard output if ocamlfind is not found