API cleanup, get rid of JsObject and GetProperty() methods that don`t return JsValue

shell/src/FiltersCommand.cpp

 #include <iostream>
 #include <sstream>
 
 #include "FiltersCommand.h"
 
 namespace
 {
   typedef std::vector<AdblockPlus::FilterPtr> FilterList;
 
   void ShowFilterList(const FilterList& filters)
   {
     for (FilterList::const_iterator it = filters.begin();
          it != filters.end(); it++)
     {
       std::string type;
-      switch ((*it)->GetProperty("type", -1))
+      switch ((*it)->GetType())
       {
         case AdblockPlus::Filter::TYPE_BLOCKING:
           type = "blocking";
           break;
         case AdblockPlus::Filter::TYPE_EXCEPTION:
           type = "exception";
           break;
         case AdblockPlus::Filter::TYPE_ELEMHIDE:
           type = "elemhide";
           break;
         case AdblockPlus::Filter::TYPE_ELEMHIDE_EXCEPTION:
           type = "elemhideexception";
           break;
         case AdblockPlus::Filter::TYPE_COMMENT:
           type = "comment";
           break;
         case AdblockPlus::Filter::TYPE_INVALID:
           type = "invalid";
           break;
         default:
           type = "(unknown type)";
           break;
       }
-      std::cout << (*it)->GetProperty("text", "(no text)") << " - " <<
+      std::cout << (*it)->GetProperty("text")->AsString() << " - " <<
           type << std::endl;
     }
   }
 }
 
 FiltersCommand::FiltersCommand(AdblockPlus::FilterEngine& filterEngine)
   : Command("filters"), filterEngine(filterEngine)
 {
 }
 
@@ skipping 54 matching lines @@
 void FiltersCommand::RemoveFilter(const std::string& text)
 {
   AdblockPlus::FilterPtr filter = filterEngine.GetFilter(text);
   if (!filter->IsListed())
   {
     std::cout << "No such filter '" << text << "'" << std::endl;
     return;
   }
   filter->RemoveFromList();
 }