Merge pull request #13 from liuzhaoguo/master

add region grow function
Refactor code
fix bug in main.py
fix bugs while refactoring, and fix a OS X bug in main.py
modify some settings
fix bug in time point selection
Merge pull request #14 from sealhuang/fix-gui-action

Refactor the structure, including add 4D data support, reduce complex signal connection, etc.
fix time selection bug in main.py
remove Unified ToolBar in Mac
Merge pull request #15 from sealhuang/fix-time-point-selection-bug

Fix time point selection bug
fix time selection bug
DOC add developer guideline document
DOC add development guidelines document
DOC fix code insertion bug
DOC fix bug in devguide.rst
DOC fix bug in devguide.rst
Merge pull request #16 from sealhuang/fix-time-selection

fix time selection bug
DOC finish development guidelines
DOC fix bugs in devguide.rst
DOC finish development guidelines