Declare DEFCALLBACK, DEFCFUN and DEFINE-FOREIGN-LIBRARY's keyword args :CCONV and :CALLING-CONVENTION obsolete, use :CONVENTION instead.

- WITH-FOREIGN-STRING's new syntax:
    with-foreign-string (binding &rest args) &body
      binding  :

Added a groveller based on Dan Knap's and Matthew Backes's cffi-grovel
and Stelian Ionescu's fork iolib-grovel.  cffi-grovel is inspired by
SBCL's groveller.  This is a preliminary version.

Includes a new wrapper generator syntax to simplify the writing of
C glue libraries among other minor features.

- Updated TODO items related to grovelling.
- Integrated documentation into the CFFI manual.
- src/libraries: use ".so" as the default library suffix.

- DEFCFUN would complain when given a docstring but no
  argument list.
- Add test.

The changes are summarized here:
http://article.gmane.org/gmane.lisp.cffi.devel/1029

Also adapted tests and examples and uffi-compat.

- Foreign Type Translators: defctype does not create Lisp types; you
  have to use eql specializers.
- enum.lisp: Use reduce in %foreign-bitfield-value.  Code a default
  rule for bitfield symbol values.

- Add a new utility function PARSE-BODY to CFFI-UTILS to pull the
  documentation string and declarations out of a body of code.
- Use CFFI-UTILS:PARSE-BODY in DEFCALLBACK.

- Callback bodies consisting of only one string literal were treated
  as docstrings instead of being returned.
- Added a test case in callbacks.lisp for this.

Thanks to ignas on #lisp for the bug report.

- Renamed make-callback to %defcallback and shifted the responsability
  of storing the address in the callback-ptr property to the cffi-sys
  backend. Previously in allegro and lispworks the host ffi's callback
  definitions were non toplevel, which is probably not right.
- Use gensyms instead of callback-symbol-name (removed that function
  from utils.lisp)

- New tests: tests/enums.lisp (4 tests) and tests/misc-types.lisp (3 tests).
- New file: objects.lisp, skeleton of the safe typed pointer interface. I
  also added a :boolean type here, it's looking for a better home still.
- (early-types.lisp): type parsers, DEFINE-TYPE-SPEC-PARSER and PARSE-TYPE.
  Added abbility to have anonymous types (ie. a name is no longer required
  for FOREIGN-TYPE). Moved DEFCTYPE to types.lisp.
- (enum.lisp): improved DEFCENUM, the values for each keyword are now
  optional, like in C. Added the anonymous type (:enum ...)
- (types.lisp):
    - Renamed :TO-C-ARG to :TO-C-DYNAMIC.
    - Renamed FOREIGN-AREF to MEM-AREF and implemented compiler macros
      for it.
    - New exported macro: DEFINE-FOREIGN-TYPE for parameterized types.
    - Change DEFINE-TYPE-TRANSLATOR back to the previous interface,
      translators take a type argument now and we have translators
      available at runtime now too.
    - FOREIGN-TYPEDEF's now inherit their parent type's translators.
    - New :wrapper type, for anonymous typedefs with translators.
- (strings.lisp): Renamed string to :string. Added new type, :string+ptr.
- (utils.lisp): renamed let-if to bif.
- (tests/callbacks.lisp): two tests were not being run for SBCL
  because I thought it triggered a bug but it's actually only one that
  triggers the bug. Fixed that.
- Updated examples and tests to use :string instead of string.

- Move #-cffi/no-foreign-funcall from cffi-tests.asd to
  tests/funcall.lisp and have the lisps that don't support this
  push the feature in cffi-<lisp>.lisp instead of defpackage.
- New file: utils.lisp
- Make Allegro, CMUCL, Corman and OpenMCL use callback-symbol-name  (from cffi-utils) to safely intern callback symbol names (James)
- Clisp: consider (pointerp NIL)