3.2.0

Main change in this release is the support of newer OCaml versions - current supported OCaml versions are from 4.03 up to 4.14 (as a consequence local (in-the-tree) build of OCaml is not supported anymore, you must have OCaml installed to build).

NB newgui2 build is finicky, see README.md for details (tl;dr system packaged OCaml and lablgtk2 or --enable-batch with OCaml 4.05)

• fix duplicated Content-Length header (#82)
• Support miniupnpc 2.2.8 (#101, Sergey Fedorov)
• upgrade upnp/natpmp libraries versions for in-the-tree build (--enable-force-upnp-natpmp)
• fix setting network-specific options from command-line (#34)
• fix build with newer (safe-string) OCaml (#98, #99, Luca Carlon)
• some internal code and build system cleanup
• CryptoPP build fixes (#62, #63, #66, Hin-Tak Leung, Jesús Pérez Rey (Chuso))
• dark theme for the web interface (Luca Carlon)