Filter Abstraction (#25)

* Add category, back filters by dictionary

* Complete internal filter set

* Fix AreaSize filter

* Populate filter object the hard way

* Manipulation flags should not be filters

* None of them need to be public

* Convert to partial helper method

* Better method use

* Field, not string; no dictionary

* Add FilterTo method for later

* More naming options (easier conversion)

* Update README

SabreTools.Library/DatItems/Machine.cs

@@ -49,6 +49,12 @@ namespace SabreTools.Library.DatItems
         [JsonProperty("publisher")]
         public string Publisher { get; set; }
 
+        /// <summary>
+        /// Category, if available
+        /// </summary>
+        [JsonProperty("category")]
+        public string Category { get; set; }
+
         /// <summary>
         /// fomof parent
         /// </summary>
@@ -138,6 +144,7 @@ namespace SabreTools.Library.DatItems
             Year = null;
             Manufacturer = null;
             Publisher = null;
+            Category = null;
             RomOf = null;
             CloneOf = null;
             SampleOf = null;
@@ -165,6 +172,7 @@ namespace SabreTools.Library.DatItems
             Year = null;
             Manufacturer = null;
             Publisher = null;
+            Category = null;
             RomOf = null;
             CloneOf = null;
             SampleOf = null;
@@ -197,6 +205,7 @@ namespace SabreTools.Library.DatItems
                 Year = this.Year,
                 Manufacturer = this.Manufacturer,
                 Publisher = this.Publisher,
+                Category = this.Category,
                 RomOf = this.RomOf,
                 CloneOf = this.CloneOf,
                 SampleOf = this.SampleOf,