The abstract_clock is now templated on a type meeting the requirements of
the Clock concept. It inherits the nested types of the Clock on which it
is based. This resolves a problem with the original design which broke the
type-safety of time_point from different abstract clocks.
* New src/ripple/crypto and src/ripple/protocol directories
* Merged src/ripple/common into src/ripple/basics
* Move resource/api files up a level
* Add headers for "include what you use"
* Normalized include guards
* Renamed to JsonFields.h
* Remove obsolete files
* Remove net.h unity header
* Remove resource.h unity header
* Removed some deprecated unity includes