Add hash as CLI function (#1995)

* Add hash as CLI function

* Use streaming SHA3.

parity/cli/mod.rs

@@ -32,6 +32,8 @@ usage! {
 		cmd_snapshot: bool,
 		cmd_restore: bool,
 		cmd_ui: bool,
+		cmd_tools: bool,
+		cmd_hash: bool,
 
 		// Arguments
 		arg_pid_file: String,
@@ -441,6 +443,8 @@ mod tests {
 			cmd_snapshot: false,
 			cmd_restore: false,
 			cmd_ui: false,
+			cmd_tools: false,
+			cmd_hash: false,
 
 			// Arguments
 			arg_pid_file: "".into(),

parity/cli/usage.txt

@@ -14,6 +14,7 @@ Usage:
   parity signer new-token [options]
   parity snapshot <file> [options]
   parity restore [ <file> ] [options]
+  parity tools hash <file>
 
 Operating Options:
   --mode MODE              Set the operating mode. MODE can be one of:
@@ -283,4 +284,3 @@ Miscellaneous Options:
   --no-color               Don't use terminal color codes in output. (default: {flag_no_color})
   -v --version             Show information about version.
   -h --help                Show this screen.
-