* Split out oputil stuff into modules based on <command>

* oputil: better syntax
* oputil: allow areaTag@storageTag for scan, e.g. oputil fb scan <args> retro_pc@some_specific_storage

core/oputil/oputil_help.js

@@ -0,0 +1,55 @@
+/* jslint node: true */
+/* eslint-disable no-console */
+'use strict';
+
+const getDefaultConfigPath			= require('./oputil_common.js').getDefaultConfigPath;
+
+exports.getHelpFor				= getHelpFor;
+
+const usageHelp = exports.USAGE_HELP = {
+	General :
+`usage: optutil.js [--version] [--help]
+                   <command> [<args>]
+
+global args:
+  --config PATH         : specify config path (${getDefaultConfigPath()})
+
+where <command> is one of:
+  user                  : user utilities
+  config                : config file management
+  file-base
+  fb                    : file base management
+
+`,
+	User : 
+`usage: optutil.js user --user USERNAME <args>
+
+valid args:
+  --user USERNAME       : specify username for further actions
+  --password PASS       : set new password 
+  --delete              : delete user
+  --activate            : activate user
+  --deactivate          : deactivate user
+`,
+
+	Config : 
+`usage: optutil.js config <args>
+
+valid args:
+  --new                 : generate a new/initial configuration
+`,
+	FileBase :
+`usage: oputil.js file-base <action> [<args>] [<action_specific>]
+
+where <action> is one of:
+  scan <args> AREA_TAG         : (re)scan area specified by AREA_TAG for new files
+                                 multiple area tags can be specified in form of AREA_TAG1 AREA_TAG2 ...
+
+valid scan <args>:
+  --tags TAG1,TAG2,...  : specify tag(s) to assign to discovered entries
+`
+};
+
+function getHelpFor(command) {
+	return usageHelp[command];
+}