Makefile: add mountainlion targets
For "Vole -d" display VOLE_DEPLOYMENT_TARGET.  Simplify some of the
information about Xcode.
XC5 project: add mountainlion configuration
Fix a bug in the Makefile: should have set -sdk option for xcodebuild
to the SDK to be used, overriding the setting in the project files.
Makefile: enable mountainlion releases. (correct a typo)
XC5 project: build 64-bit only for mavericks and mountainlion
Project (XC5) set ARCH to 64 bit for Vole_xc5