Use our own gettimeofday implementation on windows for it to be consistent across ming builds and higher resolution.
Abstract out the conversion of system time to an lldiv_t in decimicroseconds.
Use timespecs on windows as cgtimer_t to capitalise on the higher resolution clock changes.
Merge pull request #481 from kanoi/master

API mcast
Merge pull request #483 from kanoi/master

miner.php mcast + docs
README add missing mcast <arg>s
api.c fix mcast debug message bug