_NET_WM_STATE_DEMANDS_ATTENTION indicates that some action in or with
the window happened. It's a weaker hint than urgency flag of WM_HINTS,
but some applications and almost all Qt applications use it instead of
WM_HINTS' urgency flag (one example is Skype).
Initially I thought using the second precision time() function is good enough,
but to make t/113-urgent.t considerably faster (>2s vs. 0.08s), we put in a
little more effort and use gettimeofday. Otherwise, this test blocks the whole
testsuite from completing much faster on modern machines :).
eval 'package foo; use strict;' enables strict within eval, it does
not leak into the surrounding scope.
Also fix various warnings/compile errors found due to now enabled
strict and warnings.
oblique