Source cleanup on Main, Opaque and Tests in ASL package.
These files appear to be unused.
Cleaning up source code in asl/concurrent
Removed unused imports in PassKey.java
Added a catch for ClassCastExceptions when casting results from tasks.
Formatted files in asl/seedscan/database
added SampleRate check to AvailabilityMetric, checked recordLength for Blockette 1000 in MiniSeed.java (0 lengths are skipped), cleaned up formatting for metric logs
Merge branch 'dev-branch' of ssh://github.com/asl-usgs/seedscan into dev-branch