IOFile provides the same interface of old BufferedFile. It provides
extension points as pure virtual functions. Those functions are
implemented by 2 concrete subclasses: BufferedFile and GZipFile.
Saved sessions may very large, as in hundreds and even thousands of
megabyte when dealing with large queues.
Add support to save and reload sessions to gzipped files, when libz is
available.
The session serializer will output gzipped contents when the file ends
with .gz, while the input file reader (UriListParser) will accept
whatever is thrown at it.
In MinGW32 build, global::cout is WinConsoleFile. When outputing to
console, it uses WriteConsoleW, so Unicode characters are written.
Fixed memory leak in WChar<->MultiByte conversion functions. The
portion of code which uses std::cout is rewritten to use global::cout.