It was not thread safe, and it only saves a few dozen bytes
of memory per libffi-using defcfun.

Notably it merges the windows/unix grovel files, which i could only
test on linux.

Added a Windows grovel file from CRLF0710, modified from the
standalone FSBV unix file.  Minimally modified for CFFI with updated
header and package, not tested at all.

Define #'prepare-function which generates a form to make the
preparation and call into libffi.  The form looks correct but it has
not been tested yet.

1. Idea: Make a slot for libffi-type-pointer and define for all
built-in types, then define methods to make the pointer on demand for
other type classes.
2. Add slot [libffi-type-pointer] with generic function to defclass
foreign-type. 
3. New file [built-in-types.lisp] defines all built-in types, and
libffi-type-pointer :around method for typedefs/aliases.
4. New [libffi-type-pointer :around method] for foreign-struct-type.
5. New lists exported from CFFI for possible other uses, and needed
here: *other-builtin-types* *built-in-integer-types*
*built-in-float-types*.

Created a function cstruct-libffi-type-pointer that generates the
libffi-type structure for any foreign structure type, so that this
structure may be used as an argument or return call by value to a
foreign function.  It replaces the automatic generation of this
structure when defstruct is compiled or loaded (via
*defcstruct-hook*), so that it is only made when needed and cffi-fsbv
need not be loaded when the defcstruct is compiled.  The structure
will only be made once; it is bound to the plist of the type symbol
(as before), and is reused if needed again.  This function compiles
but has not yet been tested.

Generic function translate-into-foreign-memory and funtion
convert-into-foreign-memory definitions now loaded by cffi.  System
cffi-fsbv defined for calling functions with foreign structures by
value using libffi.  Current state of this system is to make
libffi-type-pointer and associate with the structure in defcstruct.
This works on test structure
(macroexpand '(defcstruct (complex :class complex-type) (real :double) (imag :double)))
but nothing further is done with the libffi-type-pointer.

To do: fix lookup-type so that if there is no type defined, it returns
nil.  Do iterate-foreign-structure in advance of macro expansion in
cstruct-libffi-hook, if any arguments lack type translation, then
return nil.  This means that that structure can not be passed/returned
by value.  Then load cif after cstruct.  Secondary bug fix: defsynonym
'unsigned to something, not sure what it's supposed to be; :uint?

- Fix :LICENSE -> :LICENCE in cffi-grovel.asd
- grovel.lisp fixes:
    * fix OpenMCL's INVOKE
    * have INVOKE call NATIVE-NAMESTRING
    * add IGNORABLE declaration to DEFINE-GROVEL-SYNTAX
- CMUCL's EXT:UNIX-NAMESTRING is buggy, don't use it.
- strings.lisp: pass missing max-octets argument to OCTET-COUNTER
  in FOREIGN-STRING-ALLOC.

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.