Added function to compute SEM of array-like data structure
Added SessionsSet class
Added mean of meansBin to SessionsSet
Added mean of meanActivity to SessionsSet
Refactored timeNorm to smooth
SessionsSet use for outputing 2 conditions
Merge branch 'feature/session-group' into develop

* feature/session-group:
  SessionsSet use for outputing 2 conditions
  Refactored timeNorm to smooth
  Added mean of meanActivity to SessionsSet
  Added mean of meansBin to SessionsSet
  Added SessionsSet class
  Added function to compute SEM of array-like data structure
Setup argument parser with sub-parsers for different tasks
Refine help display
Checkpoint 1

Mostly argument parsing and start R processing
Ignore DS_Store files
Adds support for additional options

- meanActivity
- meanMeanActivity
- meanMeansBin
Adds function for eta-square
Adds option to normalize meanBins by activity
Merge branch 'feature/argparse' into develop

* feature/argparse:
  Adds option to normalize meanBins by activity
  Adds function for eta-square
  Adds support for additional options
  Ignore DS_Store files
  Checkpoint 1
  Refine help display
  Setup argument parser with sub-parsers for different tasks