Add MixedStateCheckboxExtension; add enumeration NSCellStateValue to Cocoa module; bump version to 167.
Merge pull request #122 from declaresub/master

Add MixedStateCheckboxExtension; add enumeration NSCellStateValue to Coc...
Merge pull request #57 from macoslib/master

Merge changes
More additions to MacDiskUtil
Merge branch 'macoslib-master'