- Removed dependencies on Boost/string in mtg sources

- Removes dependencies on Boost/shared_ptr in mtg sources only for WP8 for the moment
- Various compilation fixes on WP8

projects/mtg/src/utils.cpp

@@ -390,3 +390,12 @@ std::string ensureFolder(const std::string & folderName)
     }
     return result;
 }
+
+void ReplaceString(std::string& subject, const std::string& search, const std::string& replace) {
+    size_t pos = 0;
+    while ((pos = subject.find(search, pos)) != std::string::npos) {
+         subject.replace(pos, search.length(), replace);
+         pos += replace.length();
+    }
+}
+