Updated .gitignore

https://github.com/github/gitignore/blob/56dbce3df3b19eb61563d56ce13b01e0fcbf7ae8/Objective-C.gitignore
Remove Entitlements.plist

The only entitlement key was `get-task-allow`, which was required for debugging by versions of Xcode prior to 4.2
Bumped deployment target to iOS 6.0
Remove manual memory management calls.

As of iOS 6, calls to `dispatch_release(queue)` are no longer needed.
Only build active architecture in the Debug configuration

This matches how CocoaPods compiles, and avoids issues linking the Pods library when building for the 64-bit iPhone
Queue property cleanup
Replace non-functioning ZXing with the ZXingObjC port

It's still painfully slow, but now QR decoding works.
Code sign as "iOS Developer" by default
Remove unused localization keys
Merge branch 'update'
Additional compiler warning and static analyzer flags in Common.xcconfig
Use modern view controller presentation methods in place of deprecated ones
Use modern interface orientation methods in place of shouldAutorotateToInterfaceOrientation:
Add a dedicated tick method for the clock timer, to avoid @selector ambiguity
Removed call to deprecated method which limited the frame rate of QR code capture
-Wconditional-uninitialized
-Wdirect-ivar-access
-Wobjc-interface-ivars
-Wundef
-Wreadonly-setter-attrs