Changing the AssemblyInfo adaptor name to Assembly due to concerns raised by other members in the Ensembl team. Info is too vague & therefore redundant

ENSCORESW-152. Committing the low cardinality and low row count caching framework into the core API. Implement the correct method from BaseAdaptor to have your values cached in local memory

Adding an iterator for subseqs to the Slice object. Means a lot of our code which deals with iteration of slices can delegate to this for its logic.

  Add date-stamp in output.

In warning():
  Add date-stamp in output.
  Make subroutine argument parsing work as for throw().
  Output message using warn() instead of to STDERR with printf().