Feature: NewGRF string codes for force and power.

diff -r df21d7a8351a src/newgrf_text.cpp
--- a/src/newgrf_text.cpp	Sat Aug 20 14:34:50 2011 +0200
+++ b/src/newgrf_text.cpp	Sat Aug 20 14:39:28 2011 +0200
@@ -570,6 +570,9 @@
 					case 0x16:
 					case 0x17: d += Utf8Encode(d, SCC_NEWGRF_PRINT_DWORD_DATE + code - 0x16); break;
 
+					case 0x18:
+					case 0x19: d += Utf8Encode(d, SCC_NEWGRF_PRINT_WORD_POWER + code - 0x18); break;
+
 					default:
 						grfmsg(1, "missing handler for extended format code");
 						break;
@@ -1026,6 +1029,8 @@
 			case SCC_NEWGRF_PRINT_WORD_SPEED:
 			case SCC_NEWGRF_PRINT_WORD_VOLUME:
 			case SCC_NEWGRF_PRINT_WORD_WEIGHT:
+			case SCC_NEWGRF_PRINT_WORD_POWER:
+			case SCC_NEWGRF_PRINT_WORD_FORCE:
 			case SCC_NEWGRF_PRINT_WORD_STATION_NAME:
 			case SCC_NEWGRF_PRINT_UNSIGNED_WORD:   *argv = _newgrf_textrefstack.PopUnsignedWord();  break;
 
@@ -1086,6 +1091,12 @@
 		case SCC_NEWGRF_PRINT_WORD_WEIGHT:
 			return SCC_WEIGHT;
 
+		case SCC_NEWGRF_PRINT_WORD_POWER:
+			return SCC_POWER;
+
+		case SCC_NEWGRF_PRINT_WORD_FORCE:
+			return SCC_FORCE;
+
 		case SCC_NEWGRF_PRINT_WORD_STATION_NAME:
 			return SCC_STATION_NAME;
 
diff -r df21d7a8351a src/table/control_codes.h
--- a/src/table/control_codes.h	Sat Aug 20 14:34:50 2011 +0200
+++ b/src/table/control_codes.h	Sat Aug 20 14:39:28 2011 +0200
@@ -125,6 +125,8 @@
 	SCC_NEWGRF_PRINT_WORD_SPEED,               ///< Read 2 bytes from the stack as signed speed
 	SCC_NEWGRF_PRINT_WORD_VOLUME,              ///< Read 2 bytes from the stack as signed volume
 	SCC_NEWGRF_PRINT_WORD_WEIGHT,              ///< Read 2 bytes from the stack as signed weight
+	SCC_NEWGRF_PRINT_WORD_POWER,               ///< Read 2 bytes from the stack as signed power
+	SCC_NEWGRF_PRINT_WORD_FORCE,               ///< Read 2 bytes from the stack as signed force
 	SCC_NEWGRF_PRINT_WORD_STATION_NAME,        ///< Read 2 bytes from the stack as station name
 	SCC_NEWGRF_PRINT_QWORD_CURRENCY,           ///< Read 8 bytes from the stack as currency
 	SCC_NEWGRF_PRINT_HEX_BYTE,                 ///< Read 1 byte from the stack and print it as hex