Type handler resolution is now delayed so that JdbcType is taken into account

Fail-fast is nice, but it practically prevents MyBatis from using runtime JDBC type information to resolve type handler.

Related to mybatis#9 mybatis#19

Author: harawata

src/main/java/org/apache/ibatis/mapping/ResultMapping.java

@@ -164,11 +164,6 @@ private void validate() {
         throw new IllegalStateException(
             "Cannot define both nestedQueryId and nestedResultMapId in property " + resultMapping.property);
       }
-      // Issue #5: there should be no mappings without typehandler
-      if (resultMapping.nestedQueryId == null && resultMapping.nestedResultMapId == null
-          && resultMapping.typeHandler == null) {
-        // throw new IllegalStateException("No typehandler found for property " + resultMapping.property);
-      }
       // Issue #4 and GH #39: column is optional only in nested resultmaps but not in the rest
       if (resultMapping.nestedResultMapId == null && resultMapping.column == null
           && resultMapping.composites.isEmpty()) {