cleanup proposal: get rid of GRealPtrArray, GRealArray

[David Benson <daveb idealab com>]

Hello, I know its getting late for these kinds of changes,
but I was wondering if anyone wished to discuss making
GPtrArray and GByteArray contain private members and
then get rid of the ugly casting etc in garray.c?

The new structures would be

struct _GPtrArray
{
  gpointer *pdata;
  guint     len;

  /*< private >*/
  guint     alloc;
};

struct _GArray
{
  guint8 *data;
  guint   len;

  /*< private >*/
  guint   alloc;
  guint   elt_size;
  guint   zero_terminated : 1;
  guint   clear : 1;
};


Pros:
  - makes the implementation much easier to understand.
    (this line of reasoning was provoked by a friend asking
    how GArray could possibly work since it didn't have the
    element size around...  he could've figured it out eventually
    by looking at the source, but the header file makes it look
    rather magical)

  - exposes members which would be occasionally useful for debugging

  - [optional] we could support constructing these on the stack or inline
    in objects for marginal efficiency gains

  - it's compatible with old sources and even binaries.

Cons:
  - exposes members of the array class.  (i'm not sure i think this a con tho)
  - goes against the original design of garray.  

Any supporters / detractors?

- Dave