Properly handled edge case of concurrent attempt to resume download where later thread uses bad remote repository and hence should fail resolution as opposed to consume the result of the first thread

Added config property to allow disabling feature

Deprecated Transfer.(get|set)State() and added Transfer.(get|set)Listener() instead which allows to employ per-transfer TransferListeners

Extended GetTask to optionally carry checksums for downloaded resource and made BasicRepositoryConnector and HttpTransporter make use of it when possible

Made BasicRepositoryConnector only create thread pool when actually multiple requests need processing

Introduced TransferResource.getResumeOffset() to query position at which transfer started

Introduced utility WorkerThreadFactory to help with name customization and made DefaultMetadataResolver as well as BasicRepositoryConnector make use of it

Moved NoTransporterException and NoRepositoryLayoutException into org.eclipse.aether.transfer package next to related NoRepositoryConnectorException

Introduced RepositoryLayoutFactory SPI and made basic repo connector use it to retrieve layout

Renamed TransportRequest to TransportTask etc. (requests usually have results, the Transporter methods are void so request/result doesn't really fit)

Introduced new TransporterFactory SPI along with a new basic connector building on top of it