Fix logging dependencies

* Added SLF4J dependencies and excluded commons-logging
from the spring-context dependency.
Dao Refactoring

* Renamed the SwiftRiverDao interface to JpaDao

* Changed the data type of the latitude and longitude
properties in the Place model to Double.

* Added  getSequenceNumber() for generating sequence numbers
and accompanying unit test
DTO Mapping classes

* Added classes for mapping the domain objects (entities)
to data transfer objects (DTOs). The DTOs are used for passing
data between the controllers and the service layer. As a first draft,
all the DTOs are Map<String, Object> representations

* Unit tests for the place and tag DTOs
Remove unnecessary services and tests

* The channel service and accompanying test is unnecessary.
Channels are associated with rivers and are eagerly fetched
whenever a river entity is loaded and addition/removal of channels
should be done from the river service
Add Identity DTO and package name changes

* Added DTO mapping class for the identity model

* Changed the root package of the DAO and Service
test classes to "com.ushahidi.swiftriver.core.api"