[VULNERABILITY] Parsing a long String will result in 100% CPU usage and String.test will never finish

[ChengpeiShi]

As @niftylettuce mentioned in #70
This PR update to use node-re2 to fix a very long string can cause a Denial of Service.

[Richienb]

This breaks browser support since it uses native modules.

[niftylettuce]

This issue is fixed in my maintained and modern version of this package at https://github.com/niftylettuce/url-regex-safe. You should be able to switch from url-regex to url-regex-safe now. See the updated list of options as I added some new ones, and changed a few defaults to more sensible ones (since not everyone is parsing Markdown for instance).