Implement File API

include/AdblockPlus/FileSystem.h

Index: include/AdblockPlus/FileSystem.h
===================================================================
new file mode 100644
--- /dev/null
+++ b/include/AdblockPlus/FileSystem.h
@@ -0,0 +1,34 @@
+#ifndef ADBLOCKPLUS_FILE_SYSTEM_H
+#define ADBLOCKPLUS_FILE_SYSTEM_H
+
+#include <istream>
+#include <string>
+
+#include "tr1_memory.h"
+
+namespace AdblockPlus
+{
+  class FileSystem
+  {
+  public:
+    struct StatResult
+    {
+      bool exists;
+      bool isDirectory;
+      bool isFile;
+      int64_t lastModified;
+    };
+
+    virtual ~FileSystem() {}
+    virtual std::tr1::shared_ptr<std::istream>
+      Read(const std::string& path) const = 0;
+    virtual void Write(const std::string& path,
+                       std::tr1::shared_ptr<std::ostream> data) = 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;
+  };
+}
+
+#endif