Bumps version to 2.7.3.24 and updates Changelog
flakes
Cannot use SIG_IGN to detect ignored signals.  Maybe fixes #48
Bumps version to 2.7.3.25
Pool: Always ignore SIGINT
Pool: do not override ignored signals
Bumps version to 2.7.3.26
Merge branch '2.7'

Conflicts:
	CHANGES.txt
	billiard/__init__.py
	billiard/pool.py
flakes
signal may raise OSError
Merge branch '2.7'