- buy & sell ram using bancor algorithm
- ram is no longer delgated
- fixed warning with double secondary index
- add block_timestamp_type

- udpate system contract to set initial account bw to 0
- update system contract to process new on block header
- update cleos api and get info api

* clean up configuration parameters
* use dynamic max_inline_action_size configuration parameter to limit size of inline actions
* use dynamic max_inline_action_depth to limit recursion depth of inline actions
* change deferred_trx_expiration_window parameter into a dynamic configuration parameter
* add numerator and denominator configuration parameters for later context free data discount implementation
* bill delayed transaction for the additional net usage of the eventual retirement of the deferred transaction

multisig_tests fixed, transaction_receipt::scheduled set and used, transaction_metadata::on_result changed to just std::function

The now() intrinsic was replaced with a current_time() intrinsic which returns the current time (not head block time) in microseconds since epoch.

A now() function was defined in eosiolib/system.h which returns current_time()/1000000 so that existing contracts which use now() need minimal changes.

The publication_time() intrinsic was modified to also return the time as microseconds since epoch.
The only contracts that used publication_time() so far were for tests and those tests have been updated to reflect the new meaning of publication_time() and current_time().

Also, it now checks to ensure the proposed producer schedule would actually change the schedule.

identity contracts split into parts: contact itself, read-only interface for other contracts, common lib #2562