begin refactor of proxy engine

proxychain/rqm/modify_domain_with_regex.go

@@ -0,0 +1,13 @@
+package rqm // ReQuestModifier
+
+import (
+	"ladder/proxychain"
+	"regexp"
+)
+
+func ModifyDomainWithRegex(match regexp.Regexp, replacement string) proxychain.RequestModification {
+	return func(px *proxychain.ProxyChain) error {
+		px.Request.URL.Host = match.ReplaceAllString(px.Request.URL.Host, replacement)
+		return nil
+	}
+}