Revision history for Perl extension BGS.

0.12  2017-11-14
	- eval for Storable::thaw
	- fix for bgs_wait($vpid)
	- wait with help pipe

0.11  2017-11-03
	- BGS::Future

0.10  2017-11-02
	- $BGS::limit

0.09  2017-11-02
	- bgs_wait($vpid)

0.08  2017-11-01
	- bgs_break($vpid)

0.07  2012-12-21
	- waitpid, not wait

0.06  2012-08-22
	- BGS::Limit::bgs_wait($limit): if $limit == 0, child processes are not used

0.05  2011-10-20
	- bgs_break - kill all child processes
	- BGS::Limit::bgs_call do not return kid_pid, but count of kid processes

0.04  2011-10-13
	- BGS::Limit

0.03  2010-01-17
	- bgs_call can return undef
	- without bgs_call value returning detection

0.02  2009-11-27
	- using pipe instead open
	- bgs_call return PID of child proces

0.01  2008-03-01
	- original version