add parens and module doc string

cPeristence.h:
    remove unused #define
    remove decl of cPersistenceCAPI from header and put in cPersistence.c

cPersistence.c:
    remove several unused functions and decls
    update K&R style func decls
    make func decls prototypes when needed
    add module doc string

    Remove PyErr_Occurred() check from the end of the module,
    following current best practice for Python.

   - remove %lf printf format; l can't modify %f
   - remove unused functions and macros
   - make sure decls of prototype-less functions are also valid prototypes

Add the $Id:$ to the doc string

ZServer. ZServer is no longer necessary at all.

Fixed a race condition in __call__.

If an exception raised on the server which could not be
unpickled on the client could cause the client connection to
fail.

ZServer. ZServer is no longer necessary at all.

      - It is no longer necessary to symbolically link cPickle or
        ZServer. ZServer is no longer necessary at all.

      - It is no longer necessary to symbolically link cPickle or
        ZServer. ZServer is no longer necessary at all.

      - A Zope-style INSTANCE_HOME and var directory are no longer
        needed.

      - If ZServer *is* available, the medusa monitor server can be
        used in the storage server.

      - An option, -d, was added to facilitate generation of a
        detailed debug log while running in the background.

for types.

The question is, do we even need Overridable any more?

on some platforms. Added Python wrapper modules to preserve official
names.

which will help new storage writers.

Creating the reference list when one isn't passed is a bonus.

compilers.

they are used. This is important to keep used data structures in
memory when the ZODB garbage collector is busy.

Added Id strings.

numbers.

in Catalog when a sort-index is used. Waaaa.

should seal the concurrency bug: the map was being set to None, resulting
in potentially two threads servicing the same queue and making it impossible
to reliably create a ClientStorage once the main loop is running.

items expensive.

nodes.

Optimized pickle formats (using tuple rather than tuple of tuples).

Updates Interfaces file with set operations and byValue method.

(re)Implemented new set operations and added byValue method.

Fixed bug in handling of empty BTreeItems.