Use -w for timeout on Windows.
Removed note about win32-open3.
Updated timeout code for Linux and OSX, and updated a test.
Merge branch 'master' of github.com:djberg96/net-ping
Updated solaris ping timeout.
Merge branch 'master' of github.com:djberg96/net-ping
Updated HP-UX timeout code.
Added changes so far for 1.7.3.
Merge remote-tracking branch 'upstream/master'

Conflicts: (resolved in favour of upstream changes):
	README
	lib/net/ping/external.rb
	test/test_net_ping_external.rb
Fix ICMP ENETUNREACH Bug;
Clean up tests, moving common code to test_helper;
Add tests for blackholes (that never return a packet),
Route unreachable and host unreachable;