Revert sqlite3_enable_load_extension() to its original long-standing behavior.
Add SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION which will enable only the C-API and
leave the SQL function disabled.

FossilOrigin-Name: b2ae5bfa32e608625bd177907596df3dbc2212e1
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index fe7203b..7bb15d0 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1382,13 +1382,14 @@
 #define SQLITE_AutoIndex      0x00100000  /* Enable automatic indexes */
 #define SQLITE_PreferBuiltin  0x00200000  /* Preference to built-in funcs */
 #define SQLITE_LoadExtension  0x00400000  /* Enable load_extension */
-#define SQLITE_EnableTrigger  0x00800000  /* True to enable triggers */
-#define SQLITE_DeferFKs       0x01000000  /* Defer all FK constraints */
-#define SQLITE_QueryOnly      0x02000000  /* Disable database changes */
-#define SQLITE_VdbeEQP        0x04000000  /* Debug EXPLAIN QUERY PLAN */
-#define SQLITE_Vacuum         0x08000000  /* Currently in a VACUUM */
-#define SQLITE_CellSizeCk     0x10000000  /* Check btree cell sizes on load */
-#define SQLITE_Fts3Tokenizer  0x20000000  /* Enable fts3_tokenizer(2) */
+#define SQLITE_LoadExtFunc    0x00800000  /* Enable load_extension() SQL func */
+#define SQLITE_EnableTrigger  0x01000000  /* True to enable triggers */
+#define SQLITE_DeferFKs       0x02000000  /* Defer all FK constraints */
+#define SQLITE_QueryOnly      0x04000000  /* Disable database changes */
+#define SQLITE_VdbeEQP        0x08000000  /* Debug EXPLAIN QUERY PLAN */
+#define SQLITE_Vacuum         0x10000000  /* Currently in a VACUUM */
+#define SQLITE_CellSizeCk     0x20000000  /* Check btree cell sizes on load */
+#define SQLITE_Fts3Tokenizer  0x40000000  /* Enable fts3_tokenizer(2) */
 
 
 /*