Fixed typo in line 33.  "give" to "given"

1. no longer need to specify index number
2. no longer need to specify type multiple times
3. clean up unnecessary references
4. remove member variables that are not needed
5. implement store for index
6. implement find iterator for secondary given primary key

- fix bug with eosiolib/multi_index update

libc/libcxx were not listed as dependencies on the identity test contract making highly parallel builds fail if it queued up that test before finishing the base contracts

rename eos_assert to eosio_assert, implement is_account() api, and move implementation from apply_context.hpp to .cpp