Fix JavaScript RegExp

[Jooseppi12]

There are various browsers that don't implement the newest EcmaScript standard, so the replace, match, split and search methods on a regex value are not working as expected in those browsers.

[granicz]

Just to clarify, the reason for a breaking change was updating the regex bindings to match the latest, unsupported standard. This should be fixed by reverting to using members on strings.

[Jand42]

@Jooseppi12 There is a Warn attribute added in beta7 with WIG support that could be used to annotate non-standard members. The original intent was that you can put it on proxy methods that does not behave exactly as in .NET bc of some reason, but it fits this use too better than Deprecated.