An alternative to the unity build, the classic build compiles each
translation unit individually. This adds more modules to the classic build:
* Remove unity header app.h
* Add missing includes as needed
* Remove obsolete NodeStore backend code
* Add app/, core/, crypto/, json/, net/, overlay/, peerfinder/ to classic build
Source files are moved between modules, includes changed and added,
and some code rewritten, with the goal of reducing cross-module dependencies
and eliminating cycles in the dependency graph of classes.
* Remove RippleAddress dependency in CKey_test
* ByteOrder.h, Blob.h, and strHex.h are moved to basics/. This makes
the basics/ module fully independent of other ripple sources.
* types/ is merged into protocol/. The protocol module now contains
all primitive types specific to the Ripple protocol.
* Move ErrorCodes to protocol/
* Move base_uint to basics/
* Move Base58 to crypto/
* Remove dependence on Serializer in GenerateDeterministicKey
* Eliminate unity header json.h
* Remove obsolete unity headers
* Remove unnecessary includes
