Start mri_tank_surface algorithm with a clone of ct_tank algorithm.
started phantom design chapter. Added references.
updated git ignore
update root gitignore
MRI tank left right boundary detection works for exterior tank inside surface
left right boundary detection now works better on inferior outside surface.
mri_tank writing progression
add old images that belongs to ct_tank to ct_tank (might be removed later)
update .gitignore
Merge branch 'ct_tank'

merging ct_tank to master
Merge branch 'mri_tank'

merging mri_tank to master
Merge branch 'phantom_design'

merge phantom_design into master