Move tablet eraser/pen switch code into ToolManager
Delete redundant code
protected to private
No more public Object m_pObject*
Move ToolsetWidget to MainWindow2
Rename ToolSet => ToolBox
minor
Resolve #246

License and copyright
Merge branch 'dev'
Add compiler flags  --std=c++11
Add 'override' keyword to virtual functions
Add 'm_' prefix to member variables
Code cleanup
Remove out-dated info
Misc
New signal/slot
Add 'widgets' qt package
Remove unused variables