Switch to "new RegExp" style regular expression

[josh1093]

On older versions of SpiderMonkey (I think our server was running 1.8.0) calling exec() on a RegExp object created like this

var repexp=/exp/;

throws an error. If instead your create your object like this

var repexp=new RegExp("exp");

exec() works fine.

[KevinGaudin]

Thanks a lot, I was aware of the incompatibility but never had time to find a workaround.