broke out the object cache functionality; generalized ReadOnlyVector;

finally implemented background sweeps of unreferenced cache objects;
anonymous user, when viewing profiles, now sees them as if all "privacy"
flags were switched on

setup/database.sql

@@ -40,7 +40,8 @@ CREATE TABLE globals (
     max_sig_mbr_page INT NOT NULL,
     max_conf_mbr_page INT NOT NULL,
     fp_posts INT NOT NULL,
-    num_audit_page INT NOT NULL
+    num_audit_page INT NOT NULL,
+    sig_create_lvl INT NOT NULL
 );
 
 # The audit records table.  Most "major" events add a record to this table.
@@ -1325,8 +1326,8 @@ INSERT INTO refsigftr (ftr_code, is_default, is_locked, is_hidden, require_read,
 
 # Initialize the system globals table.
 INSERT INTO globals (posts_per_page, old_posts_at_top, max_search_page, max_sig_mbr_page, max_conf_mbr_page,
-                     fp_posts, num_audit_page)
-    VALUES (20, 2, 20, 50, 50, 10, 100);
+                     fp_posts, num_audit_page, sig_create_lvl)
+    VALUES (20, 2, 20, 50, 50, 10, 100, 1000);
 
 # Add the 'Anonymous Honyak' user to the users table.
 # (Do 'SELECT * FROM users WHERE is_anon = 1' to retrieve the AC user details.)