MIAS: add method to parse masks after setId

'parseMasks(MetadataStore)' allows the mask data to be parsed and placed
in a separate MetadataStore after setId is called.  No other methods
need to be called; parseMasks intentionally does not respect the value
set by 'setAutomaticallyParseMasks(boolean)'.

See ticket #10170.
Merge pull request #372 from melissalinkert/10170

MIAS: add method to parse masks after setId