add docstring to class SeedRegionGrowing--basic
add docstring to class SeedRegionGrowing--Full version, but not test
modify the order of the class
add unique 2d to utils and add doc to neighbor
refactor neighbor module--version 2
refactor neighbor module and add doc fully -- final version
remove outdate py files
final regdoc
Merge pull request #6 from zhenzonglei/rgdoc

Docstring for SeededRegionGrowing and refactor the SpatialNeighbor