Avoid usage of eval() to comply with strict CSP

[olivierkaisin]

At the moment Replicator is breaking javascript bundles in environments where a strict Content Security Policy prevents use of eval().

The following changes fix that issue by using another method for retrieving the global object.

[jeffRTC]

@inikulin Can you merge this please? Really needed.

[jeffRTC]

@AndreyBelym Maybe you can perhaps?