Update the ImageSeriesReader documentation.
Update the ImageSeriesReader documentation.

Updated the documentation to cover the reading of meta-data
dictionaries.

Change-Id: Ie53e2820609ef7308ed72e75e4086ce6885d5b15

kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix,kaspermarstal/SimpleElastix