Merge branch 'ef/msys-imap'

* ef/msys-imap:
  Windows: use BLK_SHA1 again
  MSVC: Enable OpenSSL, and translate -lcrypto
  mingw: enable OpenSSL
  mingw: wrap SSL_set_(w|r)fd to call _get_osfhandle
  imap-send: build imap-send on Windows
  imap-send: fix compilation-error on Windows
  imap-send: use run-command API for tunneling
  imap-send: use separate read and write fds
  imap-send: remove useless uid code

diff --cc Makefile
Simple merge

diff --cc compat/vcbuild/scripts/clink.pl
Simple merge

diff --cc imap-send.c
Simple merge