CatalogParser: use File.Open with FileShare.Read to not conflict with other processes (such as antivirus)

GNU.Gettext/GNU.Gettext/Catalog/CatalogParser.cs

@@ -67,7 +67,7 @@ namespace GNU.Gettext
 			char foundchar = 'x';
 			char[] curr = new char[] {'x'};
 			
-			using (TextReader tr = new StreamReader(File.Open(fileName, FileMode.Open, FileAccess.Read),encoding))
+			using (TextReader tr = new StreamReader(File.Open(fileName, FileMode.Open, FileAccess.Read, FileShare.Read),encoding))
 			{
 				while (tr.Read (curr,0,1) != 0)
 				{