Merge branch 'enh_filetree' into 'master'

fsl/utils/filetree/__init__.py

fsl/utils/filetree/filetree.py

fsl/utils/filetree/parse.py

fsl/utils/filetree/trees/BedpostX.tree

fsl/utils/filetree/trees/Diffusion.tree

fsl/utils/filetree/trees/HCP_Surface.tree

fsl/utils/filetree/trees/HCP_directory.tree

fsl/utils/filetree/trees/ProbtrackX.tree

fsl/utils/filetree/trees/bet.tree

fsl/utils/filetree/trees/bids_raw.tree

fsl/utils/filetree/trees/dti.tree

fsl/utils/filetree/trees/eddy.tree

fsl/utils/filetree/trees/epi_reg.tree

fsl/utils/filetree/trees/fast.tree

fsl/utils/filetree/trees/freesurfer.tree

fsl/utils/filetree/trees/tbss.tree

fsl/utils/filetree/trees/topup.tree

fsl/utils/filetree/utils.py

setup.py

tests/test_filetree/custom.tree