Revert "db: increase db module level in vlib "

This reverts commit cd6d175180.

examples/database/mysql.v

@@ -1,4 +1,4 @@
-// import db.mysql
+// import mysql
 
 // pub fn main() {
 // 	conn := mysql.connect('localhost', 'root', '', 'mysql')
@@ -11,5 +11,5 @@
 // }
 
 fn main() {
-
-}
+	
+}	

examples/database/pg/customer.v

@@ -1,6 +1,6 @@
 module main
 
-import db.pg
+import pg
 
 struct Customer {
 	id int
@@ -58,3 +58,5 @@ fn main() {
 	}
 	db.insert(nc)
 }
+
+

examples/database/sqlite.v

@@ -1,22 +1,22 @@
-import db.sqlite
+import sqlite
 
 fn main() {
 	db := sqlite.connect(':memory:')
 	db.exec("create table users (id integer primary key, name text default '');")
-
+	
 	db.exec("insert into users (name) values ('Sam')")
 	db.exec("insert into users (name) values ('Peter')")
 	db.exec("insert into users (name) values ('Kate')")
-
+	
 	nr_users := db.q_int('select count(*) from users')
 	println('nr users = $nr_users')
-
+	
 	name := db.q_string('select name from users where id = 1')
 	assert name == 'Sam'
-
+	
 	users, code := db.exec('select * from users')
 	println("SQL Result code: $code")
 	for row in users {
 		println(row.vals)
-	}
-}
+	}	
+}