Internalize dependency on CommonHMAC

Fixes error: "Include of non-modular header inside framework module"
Modular imports
Additional persistence tests
Fix indentation in serialization tests
Random period fix in serialization tests
Helper method for generating secret data from a string
Move secret helper to a category on NSData
Consolidate secret helper into serialization
Merge branch 'secret-helper' into objc
Add Base32 tests
Version 1.1
Merge branch 'objc'

Conflicts:
	OneTimePassword.xcodeproj/project.pbxproj
	OneTimePassword/Legacy/OTPGenerator.h
	OneTimePassword/Legacy/OTPGenerator.m
	OneTimePassword/OTPAlgorithm.h
	OneTimePassword/OTPAlgorithm.m
	OneTimePassword/OTPToken+Serialization.m
	OneTimePassword/OneTimePassword.h
	OneTimePasswordLegacyTests/OTPTokenGenerationTests.m
	OneTimePasswordLegacyTests/OTPTokenPersistenceTests.m
	OneTimePasswordLegacyTests/OTPTokenSerializationTests.m