- make pollcat_loop() work as expected with no structs linked, by
- calling usleep() instead of poll()
- refactoring delay calculation and reset into pollcat_time_value()
- simplify pollcat_timer_dispatch() in case of slow callbacks
- deprecate pollcat_timer_dispatch_thresh
- revise tests/timer.c to support two new options:
- -s to monitor stdin with pollcat_fd_add()
- -w to use pollcat_loop() instead of handling main-loop separately
- make pollcat_dump() always present in header, since it's always compiled in
- add Makefile rules for installing tests, for easier running on cross-compiled targets