tests: Making Scheduler and TCP test cases more resilient to time

These two tests were frequently falsely failing on overloaded build bots

Change-Id: I4e6dc09a647317514a7318e09bb095c7d7e6045a
face: NDNLP encoding change

FragIndex and FragCount fields are encoded as nonNegativeInteger.

refs #1283

Change-Id: I4654078c3bfd73c83ce06ce6a9cd97952a4f49f8