BIDS-Apps/tracula v6.0.0-4

This release includes several updates:

• runs recon-all if not found in freesurfer_dir. Closes #20
• parallelizes the computation
• fixes bedpost random seed to get the exactly same results when running an analysis twice
• checks if study is truly longitudinal (or just 1 session with ses- level) and handles fs_dir names like the freesurfer app. Closes #1
• adds support for multiple bval-files per subject. Closes #5
• adds pathstats-byvoxel to group2
• should make it openneuro compatible