memcached PECL extension.

             truncated by memcache leading to collisions.

Patch thanks to David Strauss.

(Ugh, too many stupid mistakes today.)

Minimally updated README and INSTALLATION docs.
NOTE: memcache.db.inc and memcache-session.inc are note yet ported.

Minimally updated the
documentation.
Note: memcache.db.inc and memcache-session.inc have not yet been
updated.

 (this bug was breaking Mollom)
Bug #533524: Properly implement cache expiration for CACHE_TEMPORARY items

thanks to chx.

#362502 by mmcdougall and jvandyk: correctly update session memcache when data has been cleared from session

called with no parameters.

Rewrite memcached session handling for Drupal 6. Now with more comments. Added session_save_session().

Use memcache->connect() to connect to the first server. Record the result; if memcache is offline, do not try to read from or write to memcache for the remainder of the request.

Drupal 6 supports multiple watchdog implementations, which requires module.inc to be included. variable_init() calls cache_get() before the module system is online, so we cannot write errors to watchdog that early.