Merge branch 'pr/use-default-sigpipe-setting'

We used to get confused when a process called us with SIGPIPE ignored; we do want to die with SIGPIPE when the output is not read by default, and do ignore the signal when appropriate. * pr/use-default-sigpipe-setting: mingw.h: add dummy functions for sigset_t operations unblock and unignore SIGPIPE