develop the pipeline

add steps for doing:
pre-processing
computing spike counts
normalization of spike counts (convert to z-scores)
concatenate the "z-scores" across all stimuli
compute the noise correlation
minor changes in old functions and pipeline
organizing the code

indicate different part of analysis
organizing the code

minor changes
correction for stimOn

it was considering the entire signal although it has to be limited to
the stimOn part; which is fixed now.
minor changes and corrections