Make it possible to supply arguments to dumpcap

[vbennich]

I am working on a project that depends on .pcap files being in libpcap format, not pcapng.
I am using e newer wireshark so it defaults to pcapng format when pyshark is running dumpcap.

I'd like a solution where I can set dumpcap parameters:

capture = pyshark.LiveCapture(interface='eth0', custom_dumpcap_params="-P", output_file="capture.pcap")
This would force dumpcap to save the file as libpcap file.

So somehow I want to be able to change the:

def _get_dumpcap_parameters(self):
        # Don't report packet counts.
        params = ["-q"]
        if self._get_tshark_version() < version.parse("2.5.0"):
            # Tshark versions older than 2.5 don't support pcapng. This flag forces dumpcap to output pcap.
            params += ["-P"]
        if self.bpf_filter:
            params += ["-f", self.bpf_filter]
        if self.monitor_mode:
            params += ["-I"]
        for interface in self.interfaces:
            params += ["-i", interface]
        # Write to STDOUT
        params += ["-w", "-"]
        return params

from my code.

Thanks!