Update build-aux to match master.
	Ticket [#2050] Missing definition of FILE_FLAG_FIRST_PIPE_INSTANCE.
Merge branch 'master' into 4.1-dev

Conflicts:
	ChangeLog
Resolve issues [#2046] and [#2027].
[#2024] Use _off64_t for lseek64 instead of off64_t.
Resolve issues [#2021], [#2046] and [#2020].