Modified the connectivity to adjust the 2D ndarray.
Add srgtest.py, which can process the 2D data and 3D data well. The SeededRegionGrowing algorithm also been modified to make it work properly. Using the fslview tools to view the result file.
Merge pull request #22 from zhouguangfu/master

Add srgtest.py, which can process the 2D data and 3D data well.