Create initlal version of Filter program

This program allows users to filter a DAT or set of DATs based on various criteria including names, sizes, and hashes.

SabreHelper/Build.cs

@@ -208,6 +208,32 @@ Options:
   -sys=, --system=	System ID to generate from
 ");
 					break;
+				case "Filter":
+					Console.WriteLine(@"Filter - Filter DATs by inputted criteria
+-----------------------------------------
+Usage: Filter [options] [inputs]
+
+Options:
+  -h, -?, --help	Show this help dialog
+  -gn=, --game-name=	Game name to be filtered on
+  -rn=, --rom-name=	Rom name to be filtered on
+  -rt=, --rom-type=	Rom type to be filtered on
+  -sgt=, --greater=	Size greater than or equal to
+  -slt=, --less=	Size less than or equal to
+  -seq=, --equal=	Size equal to
+  -crc=, --crc=		CRC to be filtered on
+  -md5=, --md5=		MD5 to be filtered on
+  -sha1=, --sha1=	SHA-1 to be filtered on
+  -nd, --nodump		Only match nodump roms
+  -nnd, --not-nodump	Exclude all nodump roms
+
+Game name, Rom name, CRC, MD5, SHA-1 can do partial matches
+using asterisks as follows (case insensitive):
+    *00 means ends with '00'
+    00* means starts with '00'
+    *00* means contains '00'
+    00 means exactly equals '00'");
+					break;
 				default:
 					Console.Write("This is the default help output");
 					break;