Bringing some overrides up to date. [1769]

DisplayControlImpl is not quite up-to-date relative to the one shipped
in idv.jar…
Fixes for more recent IDV code. [1769]

The methods “initDataSelectionComponents”, “removeKey”, “replaceKey”,
and “getKey” have been changed to avoid compiler errors when run
against an idv.jar newer than the one McV currently “ships” with.

“setDataSelection” has also been modified to avoid problems where the
incoming DataSelection object results in the code losing track of the
geographic bounding box.
Merge pull request #95 from jon4than/inq1769

Changes for Inquiry 1769.