Fixed 3 compilation errors

Author: NikolayIT

Source/Source/Parser.cs

@@ -142,7 +142,7 @@ public bool Accept(RTFToken token , RTFReader reader )
             if ( token.Key == "emdash")
             {
                 CheckBuffer();
-                myStr.Append('—');
+                myStr.Append("—"); // TODO: Check this literal
                 return true;
             }
             if ( token.Key == "")

Source/Source/RTFNodeGroup.cs

@@ -173,16 +173,16 @@ internal void MergeText()
 						AddString( myStr , buffer );
 						// notice!! This code may cause compiler error in OS which not support chinese character.
 						// you can change to myStr.Append('-');
-						myStr.Append( '¡ª');
-						continue ;
+						myStr.Append( "¡ª"); // TODO: Check this literal
+                        continue ;
 					}
 					if( node.Keyword == "" )
 					{
 						AddString( myStr , buffer );
 						// notice!! This code may cause compiler error in OS which not support chinese character.
 						// you can change to myStr.Append('-');
-						myStr.Append( '¨C' );
-						continue ;
+						myStr.Append( "¨C" ); // TODO: Check this literal
+                        continue ;
 					}
 				}
 				AddString( myStr , buffer );