Make configurabe in restcomm-test.py which functionalities to run

[atsakiridis]

Right now there are 3 categories of things the tool does (in this order):

• Do Restcomm provisioning/unprovisioning
• Start HTTP server for external service & web app
• Spawn webrtc browsers

Often we want to avoid running all those in a single machine mainly to avoid having both Restcomm/MS and the web browsers in the same machine, as both are pretty intensive and might cause issues in the tests. Ideally we want Restcomm/MS instance to not be burdened with other stuff.

Let's introduce a bitmap variable to switch on an off those categories of functionalities in any combination we want