Issue #1596, #1720 - Make status bar menu consistent with plugin abilities

src/plugin/PluginTabBase.h

Index: src/plugin/PluginTabBase.h
===================================================================
--- a/src/plugin/PluginTabBase.h
+++ b/src/plugin/PluginTabBase.h
@@ -75,7 +75,13 @@
   void CacheFrame(const std::wstring& url);
   bool IsFrameCached(const std::wstring& url);
   void ClearFrameCache(const std::wstring& domain=L"");
-
+  /*
+   * Is it possible to disable the current content on a per-site basis?

[sergei, 2015/12/08 20:20:19]

This comment is unclear because it's not clear what the current content it is
told here about and it's not question whether it's possible or not on a per-site
basis.

Actually the method should indicate whether it makes sense and possible to
either enable or disable ABP on the current web site.

[Eric, 2015/12/09 12:48:35]

Tabs have current content displayed in the browser tab window. What's confusing
about that?
Well, that's what it says in the function name.

I've renamed the function to avoid the use of the English modal verb "can",
which likely doesn't translate easily.

+   *
+   * ABP only intercepts protocols "http:" and "https:",

[sergei, 2015/12/08 20:20:19]

I would rather move it into the method body because it explains the magic
strings used there.

[Eric, 2015/12/09 12:48:35]

Done.

+   *   so it makes no sense to offer the user an option to block content from other protocols.

[sergei, 2015/12/08 20:20:19]

I bit unusual formatting with two spaces gap.

[Eric, 2015/12/09 12:48:35]

I rewrote this piece of the comment entirely.

+   */
+  bool CanDisableOnSite();
 };
 
 /**