Accept signal names, not just numbers
Move Clock_Timer.h back into Timer.xs

The planned splitup of clocks and timers never really happened.
Add coarse and boottime clocks
Use perl's builtin reentrant error utilities
Minor refactoring
Always deliver signal to current thread if supported
Made class argument to ::Timer::_new an SV
Move timer method to XS
Improved description
Refactor create_timer
Move P::RT::T->new into XS
Refactor timer creation logic

This way, P::RT::Clock->timer doesn't have to go through a Perl call to
create a new timer
Refactor various methods into XS

Now we don't have any helper functions in perl anymore, all the code is
in XS.
Add test for timer method of clocks
Added timer example
Converted to Test::Fatal
Made Timer tests more robust
Make "realtime" the default clock in Clocks
Add handle method to Clock and Timer
v0.016

          Accept signal names, not just numbers
          Add coarse and boottime clocks
          Always deliver signal to current thread if supported
          Make "realtime" the default clock in Clocks
          Add handle method to Clock and Timer