(Experimental): implemented IPT composite images.

use LEX/YACC to parse IPT files.

Experimental/Artemis/IPT.Language.grammar.y

@@ -0,0 +1,49 @@
+%namespace GameRes.Formats.Artemis
+%partial
+%parsertype IPTParser
+%visibility internal
+%tokentype Token
+
+%union { 
+	public int n; 
+	public string s; 
+	public IPTObject o;
+}
+
+%start input
+
+%token NUMBER STRING_LITERAL IDENTIFIER
+
+%%
+
+input: root_definition ;
+
+root_definition: IDENTIFIER '=' object { RootObject[$1.s] = $3.o; }
+	       ;
+
+object: '{' { BeginObject(); }
+        decl_list optional_comma
+        '}' { EndObject(); }
+      ;
+
+decl_list: statement
+	 | decl_list ',' statement
+	 ;
+
+optional_comma: ',' | /* empty */ ;
+
+statement: definition | lvalue ;
+
+definition: IDENTIFIER '=' value { CurrentObject[$1.s] = $3.Value; }
+          ;
+
+lvalue: value { CurrentObject.Values.Add ($1.Value); }
+      ;
+
+value: object | string | number ;
+
+string: STRING_LITERAL ;
+
+number: NUMBER ;
+
+%%