CHANGE: TSAgent: Make some methods more public for easy overload

Needed when willing to do strange things with the input files: I want to
indicate in the LFN the starting event number (/vo/something/file:3445),
so I need to be able to change the getDataReplicas method as well as the
getDataReplicasRM (to strip the :XXX).
FIX: Too many public things now

As the replica cache things are very very private, it's hard to overload
the getDataReplicas. Will overload only the getDataReplicasRM that use
only semi private things
FIX: mend the 'method'

Fix the number of _
Merge pull request #1407 from sposs/TSAgentUpdate

CHANGE: TSAgent: Make some methods more public for easy overload