TrackBuilder should not write BRAM memory

[tomalin]

The TrackBuilder (implemented in https://github.com/cms-L1TK/cmssw/blob/L1TK-dev-14_0_0_pre2/L1Trigger/TrackFindingTracklet/interface/FitTrack.h ) has output streams streamTrackRaw & stubStream, corresponding to the streams in FW. It also produces a historic copy of this output which it writes to memory TrackFitMemory. This does not correspond to the FW, where there is no BRAM memory after the TrackBuilder, so all references to the TrackFitMemory should be deleted. (Or better, disabled, so they can still be used with the historic pure "Tracklet" L1 track algorithm).
To allow this to happen, the writing of txt files corresponding to the TrackBuilder output (for FW testing) should be done using the stream output (possibly from L1FPGAProducer, after it has been converted into an EDProduct) instead of the TrackFitMemory::writeTF() function.

The existing code is unnnecessary complicated, with the TrackBuilder produces two alternative outputs, only one of which corresponds to the FW. The TrackFitMemory is also incapable of representing any gaps in the data stream.