move some algorithms(region_grow,watershed,localmax,edge_detection) from menu bar to bottom-left tools box
add segmentationwidget to toolbox
add statswidget to toolbox
move roifilter and roimerge to ROItools of tools box
Merge pull request #36 from liuzhaoguo/move_algorithms_to_tools_box

move algorithms to bottom-left tools box.
HLJ: Well done!