util: Add setcap_net_raw API

Some binaries such as osmo-bts-ocpty require specific capabilities, and
we need to provide them in case osmo-gsm-tester is not run as root.

Process class from process module is imported inside the method after
module initialization in order to avoid circular dependency of relative
imports, which is only available since python 3.5.

Change-Id: If3eb24461c02173dc80837a4cc83f9f2420c7816
1 file changed