Make build from command line using xcodebuild

#####1. Prerequisites

1). use xcodebuild -showsdks to get a list of sdk.

2). set up the right provisioning profile in xcode project.

#####2. Pick the right SDK

sudo xcode-select -s /Applications/Xcode6-Beta5.app

#####3. Make the build

xcodebuild -project POC_iPhoto.xcodeproj -target POC_iPhoto -sdk iphoneos8.0

#####4. Create the ipa file

/usr/bin/xcrun -sdk iphoneos8.0 PackageApplication -v /Users/atk847/Documents/WorkSpaces/iOS/POC_iPhoto8/build/Release-iphoneos/POC_iPhoto.app -o /Users/atk847/Documents/WorkSpaces/iOS/POC_iPhoto8/build/Release-iphoneos/POC_iPhoto.ipa