Revision 1700740

In the kwallet code: Initialize the wallet cache once, instead
of every time we get or save a password. Cache the wallet in the
parameter hash and its pool instead of the single invocation pool.

This patch is in response to an issue
Found by: James McCoy <jamessan{_AT_}debian.org>

* subversion/libsvn_auth_kwallet/kwallet.cpp
  (kwallet_terminate): Add forward definition.
  (get_wallet): Register pool cleanup handler once, and only when we set
    the wallet. Register cleanup on the hash pool.
  (kwallet_terminate): Completely cleanup.

  (kwallet_password_get,
   kwallet_password_set): Don't add another cleanup hook on every invocation.