Integration of dbunit, h2 and spring profiles

Aimed at improving development environment with the following changes:
- Introduced two spring profiles, "dev" and "prod"

**Profile "dev":**
- Affects mainly datastore module. Breaks mysql dependency and creates and initialize in memory H2 databse. Intended to use for all testing purposes and local development activities
- Must be careful to use @ActiveProfiles annotation in the module where spring application context is being initialized.
- See unit and integration tests in datastore module for reference

**Profile "prod":**
- Uses mysql database, i.e. original settings
- webapp is configured to activate "prod" profile as default. See web.xml

Also:

- Integrated dbunit to import predefined datasets for all development and testing purposes. See datastore tests for reference

- Configured surefire and failsafe plugins for datastore module to run unit and integration tests and collect coverage metrics