add support to compile the Objective-C source codes which uses Modules syntax in `app.vendor_project' with Xcode 5.
add support to compile the Objective-C source codes which uses Modules syntax in `app.vendor_project' with Xcode 5.

http://clang.llvm.org/docs/Modules.html

This patch supports support Objective-C Modules when compile ObjC source codes without xcodeproj file, like
https://github.com/Watson1978/RubyMotionKaigi2013

HipByte/RubyMotion,katsuyoshi/RubyMotion,jjaffeux/RubyMotion,incbee/RubyMotion,hboon/RubyMotion,katsuyoshi/RubyMotion,jjaffeux/RubyMotion,beni55/RubyMotion,hboon/RubyMotion,jjaffeux/RubyMotion,beni55/RubyMotion,HipByte/RubyMotion,hboon/RubyMotion,incbee/RubyMotion,beni55/RubyMotion,HipByte/RubyMotion,jjaffeux/RubyMotion,incbee/RubyMotion,katsuyoshi/RubyMotion,beni55/RubyMotion,incbee/RubyMotion,katsuyoshi/RubyMotion