allow _CR file now to be either png or jpg
commits with main changes to allow for varying jpeg/png/?? formats in: (a) the img data sent from browser [typically will be jpeg, but may revert to png], and (b) the actual original file.   due to needs of matching algorithm, the _CR file and the original must be in same format.

note: this commit is a first step; next commit will delete EncounterCR servlet as it is effectively retired at this point.
cleaned up some rubbish
EncounterCR has been retired. functionality is now within EncounterAddMantaPattern
merge, including png/jpg changes to EncounterAddMantaPattern servlet