Tidy up includes and add modules to the classic build:

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

src/ripple/app/data/DBInit.cpp

@@ -17,6 +17,10 @@
 */
 //==============================================================================
 
+#include <BeastConfig.h>
+#include <ripple/app/data/DBInit.h>
+#include <type_traits>
+
 namespace ripple {
 
 // Transaction database holds transactions and public keys

src/ripple/app/data/Database.cpp

@@ -17,6 +17,10 @@
 */
 //==============================================================================
 
+#include <BeastConfig.h>
+#include <ripple/basics/StringUtilities.h>
+#include <ripple/app/data/Database.h>
+
 namespace ripple {
 
 Database::Database (const char* host)

src/ripple/app/data/Database.h

@@ -21,6 +21,9 @@
 #define RIPPLE_DATABASE_H_INCLUDED
 
 #include <ripple/basics/Blob.h>
+#include <cstdint>
+#include <string>
+#include <vector>
 
 namespace ripple {
 

src/ripple/app/data/DatabaseCon.cpp

@@ -17,7 +17,9 @@
 */
 //==============================================================================
 
+#include <BeastConfig.h>
 #include <ripple/app/data/DatabaseCon.h>
+#include <ripple/app/data/SqliteDatabase.h>
 
 namespace ripple {
 

src/ripple/app/data/DatabaseCon.h

@@ -20,8 +20,9 @@
 #ifndef RIPPLE_DATABASECON_H
 #define RIPPLE_DATABASECON_H
 
+#include <ripple/app/data/Database.h>
 #include <ripple/core/Config.h>
-
+#include <boost/filesystem/path.hpp>
 #include <mutex>
 #include <string>
 

src/ripple/app/data/SqliteDatabase.cpp

@@ -17,6 +17,7 @@
 */
 //==============================================================================
 
+#include <BeastConfig.h>
 #include <ripple/app/data/SqliteDatabase.h>
 #include <ripple/core/JobQueue.h>
 #include <ripple/basics/Log.h>

src/ripple/app/data/SqliteDatabase.h

@@ -20,6 +20,10 @@
 #ifndef RIPPLE_SQLITEDATABASE_H_INCLUDED
 #define RIPPLE_SQLITEDATABASE_H_INCLUDED
 
+#include <ripple/app/data/Database.h>
+#include <ripple/basics/Blob.h>
+#include <ripple/core/JobQueue.h>
+#include <beast/module/sqlite/sqlite.h>
 #include <beast/threads/Thread.h>
 #include <mutex>