introduce serverpath macro

for now, computes path to backup directory, appending the relative path
of UploadBackupDir to the absolute one from the UploadURL

Also added example for store.php to hint

core/language/en-GB/ControlPanel.multids

@@ -56,12 +56,11 @@ Saving/TiddlySpot/Backups: Backups
 Saving/TiddlySpot/Description: These settings are only used when saving to http://tiddlyspot.com or a compatible remote server
 Saving/TiddlySpot/Filename: Upload Filename
 Saving/TiddlySpot/Heading: ~TiddlySpot
-Saving/TiddlySpot/Hint: //The server URL defaults to `http://<wikiname>.tiddlyspot.com/store.cgi` and can be changed to use a custom server address//
+Saving/TiddlySpot/Hint: //The server URL defaults to `http://<wikiname>.tiddlyspot.com/store.cgi` and can be changed to use a custom server address, e.g. `http://me.com/store.php`.//
 Saving/TiddlySpot/Password: Password
 Saving/TiddlySpot/ServerURL: Server URL
 Saving/TiddlySpot/UploadDir: Upload Directory
 Saving/TiddlySpot/UserName: Wiki Name
-Saving/TiddlySpot/RelativeURL: relative to ''Server URL''
 Settings/AutoSave/Caption: Autosave
 Settings/AutoSave/Disabled/Description: Do not save changes automatically
 Settings/AutoSave/Enabled/Description: Save changes automatically

core/modules/macros/serverpath.js

@@ -0,0 +1,41 @@
+/*\
+title: $:/core/modules/macros/serverpath.js
+type: application/javascript
+module-type: macro
+
+Outputs a server-path based on parameters,
+by default appends a relative path to an absolute one,
+e.g. constructs path to TiddlySpot backup directory
+
+\*/
+(function(){
+
+/*jslint node: true, browser: true */
+/*global $tw: false */
+"use strict";
+
+exports.name = "serverpath";
+
+exports.params = [
+	{name: "source"},
+	{name: "target"},
+	{name: "mode"}
+];
+
+/*
+Run the macro
+*/
+exports.run = function(source, target, mode) {
+	var result = target;
+	mode = mode || "";
+	switch (mode){
+		case "":
+		case "append-relative":
+			target = ("." == target || "./" == target) ? "" : target;
+			result = source.substr(0,1+source.lastIndexOf('/')) + target;
+			break;
+	}
+	return result;
+};
+
+})();

core/ui/ControlPanel/Saving.tid

@@ -10,10 +10,10 @@ http://$(userName)$.tiddlyspot.com/backup/
 <$reveal type="nomatch" state="$:/UploadName" text="">
 <$set name="userName" value={{$:/UploadName}}>
 <$reveal type="match" state="$:/UploadURL" text="">
-<a href=<<backupURL>>><$macrocall $name="backupURL" $type="text/plain" $output="text/plain"/></a>
+<<backupURL>>
 </$reveal>
 <$reveal type="nomatch" state="$:/UploadURL" text="">
-<<lingo TiddlySpot/RelativeURL>>
+<$macrocall $name=serverpath source={{$:/UploadURL}} target={{$:/UploadBackupDir}}>>
 </$reveal>
 </$set>
 </$reveal>
@@ -33,5 +33,4 @@ http://$(userName)$.tiddlyspot.com/backup/
 |<<lingo TiddlySpot/UploadDir>> |<$edit-text tiddler="$:/UploadDir" default="." tag="input"/> |
 |<<lingo TiddlySpot/BackupDir>> |<$edit-text tiddler="$:/UploadBackupDir" default="." tag="input"/> |
 
-<<lingo TiddlySpot/Hint>>
-
+<<lingo TiddlySpot/Hint>>