xPrepareSql: require iVersion >= 700

Following @psarna's advice, use iVersion >= 700 for
community-contributed methods.

Author: lucasvr

src/sqlite.h.in

@@ -7076,7 +7076,8 @@ struct sqlite3_module {
   /* The methods above are in versions 1 and 2 of the sqlite_module object.
   ** Those below are for version 3 and greater. */
   int (*xShadowName)(const char*);
-  /** The methods below are for version 4 and greater. */
+  /* The methods below relate to features contributed by the community and
+  ** are available for version 700 and greater. */
   int (*xPrepareSql)(sqlite3_vtab_cursor*, const char*);
 };
 

src/test8.c

@@ -1332,7 +1332,7 @@ static sqlite3_module echoModule = {
 };
 
 static sqlite3_module echoModuleV2 = {
-  4,                         /* iVersion */
+  700,                       /* iVersion */
   echoCreate,
   echoConnect,
   echoBestIndex,

src/vdbe.c

@@ -8095,7 +8095,7 @@ case OP_VPrepareSql: {
   pModule = pVtab->pModule;
 
   /* Invoke the xPrepareSql method */
-   if( pModule->iVersion>=4 ){
+   if( pModule->iVersion>=700 ){
     if( pModule->xPrepareSql && p->zSql ){
       rc = pModule->xPrepareSql(pVCur, p->zSql);
       if( rc ) goto abort_due_to_error;