Add AppKit version numbers.
Vole.h: add VOLE_DEPLOYMENT_TARGET requirement
Add VOLE_DEPLOYMENT_TARGET to the preprocessor macros for Xcode-3 builds.
Add VOLE_DEPLOYMENT_TARGET to the preprocessor macros for Xcode-5 builds
(Mavericks and Mountain Lion)
All the changes reqired to conditionally compile ImageAndTexTCell
depending on the OSX deployment target. The preprocessor macros
in the Project files must be kept in step with MOSXDT in the Makefile.