[ModelFitting] on centreline
Paralleling Vesslness
Add macro INPUT_DIR and OUTPUT_DIR
Bug fix in IP:normalize(...)
Merge branch 'master' into develop
Merge branch 'master' of https://github.com/yzhong52/Thin_Vessel_Segmentation into develop

Conflicts:
	VesselNess/main.cpp
[ModelFitting] init label to centreline
change rendering mode for GLLineModel
Created a synthetic bifurcation :)
update eigen_deomp.h
Begin experiment about bifurcation
code clean up; add comments
code clean up; add comments and etc.
update datacost funct
code clean up - energy functions
using function pointer for energy functions
abs_eps smooth cost
using function pointers in both EnergyFunctions.h and LevenburgMaquart.h
code clean up; rename function names;
[Show Yuri] This experiment shows that linear version of the smooth cost is enhance the result a lot better than the quadratic version. I need to show this to Yuri and ask him.