Import Update: Add another kind of GH for condition
Remove useless fucitons and files:
remove treefile_marry
remove treefile_income
remove treefile_DOBMM
remove treefile_DOBYY
remove treefile_EDUCYEAR
remove treefile_SEX
remove treefile_RACEX

Modify maketree.py
Add even distribution tree make fuction gen_even_tree
This fuction divide generalization hierarchies by fan-out.
Default fanout = 5, for small data set fanout = 4

Modify read_data.py
Remove useless reading part for QID, keep SA remain.