Issue 54 deployment artifact from bamboo specs (now with fixed tests)

Issue #54: Check stored plugin artifact format for task editor context

The edit context in AutoDeployConfigurator create an AvailableArtifact from a stored string. The string did not match the expected format the task editor used to fail with an internal server error.

Issue #54: Retrieve deployment artifacts by name for bamboo specs

The method getFileFromArtifacts expects string containing the artifactId, what does not work for bamboo specs. If the artifactString does not match the format, the method tries to retrieve the artifact by name

Issue #54: Use v2 prefix for test values in TestDefaultConfigurationValidator

Issue #54: Allow negative ids in AvailableArtifact.isValidStoredArtifact