Implement File API

include/AdblockPlus/FileSystem.h

Index: include/AdblockPlus/FileSystem.h
===================================================================
rename from include/AdblockPlus/FileReader.h
rename to include/AdblockPlus/FileSystem.h
--- a/include/AdblockPlus/FileReader.h
+++ b/include/AdblockPlus/FileSystem.h
@@ -1,5 +1,5 @@
-#ifndef ADBLOCKPLUS_FILE_READER_H
-#define ADBLOCKPLUS_FILE_READER_H
+#ifndef ADBLOCKPLUS_FILE_SYSTEM_H
+#define ADBLOCKPLUS_FILE_SYSTEM_H
 
 #include <istream>
 #include <string>
@@ -7,11 +7,24 @@
 
 namespace AdblockPlus
 {
-  class FileReader
+  class FileSystem
   {
   public:
-    virtual ~FileReader();
+    struct StatResult
+    {
+      bool exists;
+      bool isDirectory;
+      bool isFile;
+      int64_t lastModified;
+    };
+
+    virtual ~FileSystem() {}
     virtual std::auto_ptr<std::istream> Read(const std::string& path) const = 0;
+    virtual void Write(const std::string& path, const std::string& content) = 0;
+    virtual void Move(const std::string& fromPath,
+                      const std::string& toPath) = 0;
+    virtual void Remove(const std::string& path) = 0;
+    virtual StatResult Stat(const std::string& path) const = 0;
   };
 }