Database initialization tool
In this change, we have write a small tool to import XML based data into database.
1. The first step is to separate the content in dal-jpa-context.xml into two separate files. That is because JPA and that small tool operates on the same database, but uses a different methodology. The original dal-jpa-context.xml will be used to address the context specifically used for Spring Data JPA, and the shared datasource information will be recorded in file dal-datasource-context.xml. (Maybe we will use different databases in future, e.g. for testing)
2. Add the test project which will contain all tools/base classes for testing.
3. Add db-init project, which is used to initialize db with OOB data.
4. Add db-init-data project, which is used contain all OOB datas.

Next step:
1. During testing, using a different database other than egoods. In that case, running test cases will not pollute database egoods
2. Refine init-postgres.sh and reinit-postgres.sh. For now, these two scripts will only populate tables. We will use the tool created in this change to insert predefined data into these database tables. This will help developers a lot.
3. Implement category service.