3.1.5

• fixed build error and shared library on cygwin (e1c9803)
• support windows native binary (0a7d63f)
  • use MinGW32 with Code::Blocks workspace
• fixed wrong db close when database file not found (e4d653f)
• fixed libiconv link on cygwin (bff9a88)
• fixed access uninitialized variable (a8566ec)