Exposing all RPCs over dapps port as CLI option (#4346)

* Exposing all RPC over dapps port as CLI option

* Fix test.

parity/cli/mod.rs

@@ -184,6 +184,7 @@ usage! {
 			or |c: &Config| otry!(c.dapps).user.clone().map(Some),
 		flag_dapps_pass: Option<String> = None,
 			or |c: &Config| otry!(c.dapps).pass.clone().map(Some),
+		flag_dapps_apis_all: bool = false, or |_| None,
 
 		// -- Sealing/Mining Options
 		flag_author: Option<String> = None,
@@ -629,6 +630,7 @@ mod tests {
 			flag_dapps_path: "$HOME/.parity/dapps".into(),
 			flag_dapps_user: Some("test_user".into()),
 			flag_dapps_pass: Some("test_pass".into()),
+			flag_dapps_apis_all: false,
 
 			// -- Sealing/Mining Options
 			flag_author: Some("0xdeadbeefcafe0000000000000000000000000001".into()),

parity/cli/usage.txt

@@ -171,6 +171,9 @@ API and Console Options:
                                  conjunction with --dapps-user. (default: {flag_dapps_pass:?})
   --dapps-path PATH              Specify directory where dapps should be installed.
                                  (default: {flag_dapps_path})
+  --dapps-apis-all               Expose all possible RPC APIs on Dapps port.
+                                 WARNING: INSECURE. Used only for development.
+                                 (default: {flag_dapps_apis_all})
 
 Sealing/Mining Options:
   --author ADDRESS               Specify the block author (aka "coinbase") address