Add Hodoscop Time of Flight calculation

Conversion of h_tof.f to THcHodoscope::CoarseProcess method.

 Quick summary of third version at  branch zafar1:

 New functions in THcScintillatorPlane.h
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    TClonesArray* GetPosADC() { return fPosADCHits;}; // Ahmed
    TClonesArray* GetNegADC() { return fNegADCHits;}; // Ahmed
    TClonesArray* GetPosTDC() { return fPosTDCHits;}; // Ahmed
    TClonesArray* GetNegTDC() { return fNegTDCHits;}; // Ahmed

 New data members in THcHodoscope.h
 ----------------------------------
    TClonesArray* scinPosADC; // Ahmed
    TClonesArray* scinNegADC; // Ahmed
    TClonesArray* scinPosTDC; // Ahmed
    TClonesArray* scinNegTDC; // Ahmed

 Action in THcHodoscope::CoarseProcess
 -------------------------------------
 scinPosADC = fPlanes[ip]-GetPosADC();
 hitPaddle  = (THcSignalHit*)scinPosADC->At(ihit))->GetPaddleNumber()-1;