#SB-90 Implement facility for managing keys in the keystore and truststore

Configured the unboundid-maven-plugin to run using SSL so that the trust/keystore functionality could be tested.
#SB-154: Implement a storage booter to be used for testing
#SB-151: Make the integration tests for the location resolvers execute the tests against different repositories
Removed the ServiceLoader approach, as it is inefficient for this case.
#SB-149: Add support for in-memory repositories

Implemented.
#SB-148: Add support for hosted repositories

Implemented.
Polished the web.xml.
Implemented a convenience method for getting a repository by name.
#SB-148: Add support for hosted repositories
#SB-149: Add support for in-memory repositories

Implemented.
#SB-115: Implement a class that creates the directory structure for a repository

Implemented.
#SB-115: Implement a class that creates the directory structure for a repository

Indentation.
Made the GenericParser thread safe.
#SB-112: Add the licensing header to all classes

- Added licensing info to the pom.xml-s.
- Added CONTRIBUTING file describing the rules of contribution.
Fixed a cause for NPE in the strongbox-security modules.