Introduced dev and prod profiles to increase configurability

Details
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- Added H2 in memory database support to use for all testing and local
development activities. MYSQL is used only if "prod" profile is activated
For webapp, default profile is set to "prod" in web.xml

- Addded dbunit to bring database to a initial state with predefined dataset
See datastore/src/test/dataset for examples

- Necessary modifications done to manage datasource configurations in
datastore module

- Introduced mockito to be able to isolate controllers in webapp module
in unit testing. There is no need to load the whole servlet context which
also has a dependency to datastore services

- Surefire and failsafe plugins activated in the datastore module

- Splitted webapp application servlet configuration file into multiple
configuration files considering their intent. It will make it easier to
change in the future

Ticket
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