Adds the min iOS deployment target of 5.0 for xcode compilation. This seems to resolve crashes where exceptions are not caught when they should be.
	Change on 2014/06/18 by kstanger <kstanger@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=69460534
Fixed warnings found with -Wshorten-64-to-32 flag.
	Change on 2014/06/18 by tball <tball@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=69469620
Issue 379: return null for out-of-range HTTP response header indices, instead of NPE.
	Change on 2014/06/18 by tball <tball@google.com>
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Created by MOE: http://code.google.com/p/moe-java
MOE_MIGRATED_REVID=69471678