Support template file

In current version, template file(vm file) does not support.

For example:

• CityMapper-findByState.vm

select
  id, name, state, country
from
  city
where
  state = @{state}

• Mapper

@Select("#parse('/mappers/CityMapper-findByState.vm')")
City findByState(@Param("state") String state);

In above case, @{state} cannot translate to JDBC bind variable (?).

We will consider to support a template file(.vm) like as mybatis-freemarker and mybatis-thymeleaf.

Start with the .vm example and the Mapper method using @Select and @Param. Compare the template-file handling in mybatis-freemarker and mybatis-thymeleaf, then determine the project entry points involved in translating @{state} into a JDBC bind variable. Done means .vm templates can be used through @Select with parameters bound correctly.