move query builders to proper locations

core/src/main/java/jef/platform/base/query/QueryBuilder.java

@@ -1,4 +1,4 @@
-package jef.query;
+package jef.platform.base.query;
 
 import jef.expressions.AndExpression;
 import jef.expressions.BinaryExpression;

core/src/main/java/jef/query/MysqlQueryBuilder.java

@@ -1,5 +0,0 @@
-package jef.query;
-
-public class MysqlQueryBuilder extends QueryBuilder {
-
-}

mysql/src/main/java/jef/platform/mysql/query/MysqlQueryBuilder.java

@@ -0,0 +1,7 @@
+package jef.platform.mysql.query;
+
+import jef.platform.base.query.QueryBuilder;
+
+public class MysqlQueryBuilder extends QueryBuilder {
+
+}