AWS: Add command for setting credentials profile

plugins/tiddlywiki/aws/docs/help.tid

@@ -9,6 +9,16 @@ Perform operation on Amazon Web Services
 --aws <sub-command> [<parameter> ...]
 ```
 
+! "profile" subcommand
+
+Sets the AWS credentials profile to be used for subsequent commands.
+
+```
+--aws profile <profile-name>
+```
+
+* ''profile-name'': AWS profile name
+
 ! "s3-load" subcommand
 
 Load tiddlers from files in an S3 bucket.

plugins/tiddlywiki/aws/modules/command.js

@@ -42,6 +42,15 @@ Command.prototype.execute = function() {
 
 Command.prototype.subCommands = {};
 
+// Set credentials profile
+Command.prototype.subCommands["profile"] = function() {
+	var AWS = require("aws-sdk"),
+		profile = this.params[1],
+		credentials = new AWS.SharedIniFileCredentials({profile: profile});
+	AWS.config.update({credentials: credentials});
+	this.callback(null);
+};
+
 // Load tiddlers from files in an S3 bucket
 Command.prototype.subCommands["s3-load"] = function() {
 	var self = this,