[Fix] Adds deployment_target attributes
[Add] Updates to r121 & removes SBJson dependency for iOS ≥ 5.0 or OS X ≥ 10.7

This allows older clients to still use ~> 0.0.1 while newer clients can
use the latest (or ~> 0.1.0).
Merge pull request #9201 from grigutis/master

GTMHTTPFetcher & gtm-oauth2