Enable cross compiling of third-party dependencies

- Change third-party CMakeLists.txt to handle building
  with cross compiler
- Build libuv, msgpack and luajit with TARGET compiler
- Build a luarocks and luajit (for the interpreter) with
  the HOST compiler
Add support the PDCurses curses library
Remove include for sys/select.h in vim.h

- There is no need to include sys/select.h anymore
Remove pthread fatal check from CMakeLists.txt
Play with travis for mingw
Fix bash exp