Remove all calls to _GTMDevLog
Test Base32 encoding/decoding with values from RFC 4648
Use a standalone pod for Base32 decoding
Remove the Base32 categories and use the external versions directly.

This requires a slight change to the OTPToken validation method, because nil secret strings can now produce non-nil (but empty) secrets.
Merge branch 'base32' into gtm-dependencies
Replace GTMNSScanner dependency with a call to strtoull()
Replace GTMNSString+URLArguments dependency with a category method
Replace gtm_httpArgumentsString dependency with a category method
Replace gtm_dictionaryWithHttpArgumentsString and gtm_stringByUnescapingFromURLArgument dependencies with category methods
Remove Google Toolbox from the podfile
Merge branch 'gtm-dependencies'