adding api to get recent transactions by id

libraries/app/database_api.cpp

@@ -331,6 +331,15 @@ processed_transaction database_api::get_transaction( uint32_t block_num, uint32_
    return my->get_transaction( block_num, trx_in_block );
 }
 
+optional<signed_transaction> database_api::get_recent_transaction_by_id( const transaction_id_type& id )const
+{
+   try {
+      return my->_db.get_recent_transaction( id );
+   } catch ( ... ) {
+      return optional<signed_transaction>();
+   }
+}
+
 processed_transaction database_api_impl::get_transaction(uint32_t block_num, uint32_t trx_num)const
 {
    auto opt_block = _db.fetch_block_by_number(block_num);

libraries/app/include/graphene/app/database_api.hpp

@@ -121,6 +121,13 @@ class database_api
        */
       processed_transaction get_transaction( uint32_t block_num, uint32_t trx_in_block )const;
 
+      /**
+       * If the transaction has not expired, this method will return the transaction for the given ID or
+       * it will return NULL if it is not known.  Just because it is not known does not mean it wasn't
+       * included in the blockchain.
+       */
+      optional<signed_transaction> get_recent_transaction_by_id( const transaction_id_type& id )const;
+
       /////////////
       // Globals //
       /////////////
@@ -480,6 +487,7 @@ FC_API(graphene::app::database_api,
    (get_block_header)
    (get_block)
    (get_transaction)
+   (get_recent_transaction_by_id)
 
    // Globals
    (get_chain_properties)