REQEXP logic error

```
In _Custom.cs the second == in the line should be a != like:

  if ( oRegex == null || oRegex.ToString() != zRegex )

Otherwise oRegex doesn't get recreated when zRegex changes.

```

Original issue reported on code.google.com by `John.Tho...@gmail.com` on 4 Feb 2013 at 5:57
