refactoring to avoid flag definition clash

[phaus]

should fix #335 335

[tomasbanet]

Hey. Any updates on this PR? Running into this issue while trying to use https://pkg.go.dev/cloud.google.com/go@v0.103.0/httpreplay (issue at googleapis/google-cloud-go#6501). So far my work-around consists of changing the Init function to:

// Init runs common initialization code for a martian proxy.
func Init() {
	level := flag.Int("v", 0, "log level")
	flag.Parse()
	mlog.SetLevel(*level)
}

[chrisivens]

Does this really need to bump to golang v1.18? Can it perhaps only go as far as v1.17? Some packages aren't yet ported to 1.18 fully yet.

[thenakulchawla]

Since this change is merged, will a new tag get created so we can pull the right version in? Thanks.