add options for ECS full subnet mask in server & TLS verification bypass in client (#92)

* add ECS full size & limit filtering

* add tls certification bypass in configuration

* flush log lines

* changes following pull request comments

* with fmt and reorg of libs in client.go

doh-client/config/config.go

@@ -47,15 +47,16 @@ type upstream struct {
 }
 
 type others struct {
-	Bootstrap        []string `toml:"bootstrap"`
-	Passthrough      []string `toml:"passthrough"`
-	Timeout          uint     `toml:"timeout"`
-	NoCookies        bool     `toml:"no_cookies"`
-	NoECS            bool     `toml:"no_ecs"`
-	NoIPv6           bool     `toml:"no_ipv6"`
-	NoUserAgent      bool     `toml:"no_user_agent"`
-	Verbose          bool     `toml:"verbose"`
-	DebugHTTPHeaders []string `toml:"debug_http_headers"`
+	Bootstrap             []string `toml:"bootstrap"`
+	Passthrough           []string `toml:"passthrough"`
+	Timeout               uint     `toml:"timeout"`
+	NoCookies             bool     `toml:"no_cookies"`
+	NoECS                 bool     `toml:"no_ecs"`
+	NoIPv6                bool     `toml:"no_ipv6"`
+	NoUserAgent           bool     `toml:"no_user_agent"`
+	Verbose               bool     `toml:"verbose"`
+	DebugHTTPHeaders      []string `toml:"debug_http_headers"`
+	TLSInsecureSkipVerify bool     `toml:"insecure_tls_skip_verify"`
 }
 
 type Config struct {