document sslserver and sslpath configuration options

README

@@ -1111,6 +1111,9 @@ path: Path part of theme URLs, before the theme name. Relative to the
     which means to use the site path + '/theme'.
 ssl: Whether to use SSL for theme elements. Default is null, which means
     guess based on site SSL settings.
+sslserver: SSL server to use when page is HTTPS-encrypted. If
+    unspecified, site ssl server and so on will be used.
+sslpath: If sslserver if defined, path to use when page is HTTPS-encrypted.
 
 javascript
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@@ -1122,6 +1125,9 @@ path: Path part of Javascript URLs. Defaults to null,
     which means to use the site path + '/js/'.
 ssl: Whether to use SSL for JavaScript files. Default is null, which means
     guess based on site SSL settings.
+sslserver: SSL server to use when page is HTTPS-encrypted. If
+    unspecified, site ssl server and so on will be used.
+sslpath: If sslserver if defined, path to use when page is HTTPS-encrypted.
 
 xmpp
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@@ -1405,8 +1411,9 @@ dir: directory to write backgrounds too. Default is '/background/'
     subdir of install dir.
 path: path to backgrounds. Default is sub-path of install path; note
     that you may need to change this if you change site-path too.
-ssl: Whether or not to use HTTPS for background files. Defaults to
-    null, meaning to guess from site-wide SSL settings.
+sslserver: SSL server to use when page is HTTPS-encrypted. If
+    unspecified, site ssl server and so on will be used.
+sslpath: If sslserver if defined, path to use when page is HTTPS-encrypted.
 
 ping
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