hdf5_der

[svn-r20560] *** H5timer.c refactoring ***

- Removed H5_now() function since it's largely a wrapper around time().  Replaced the two calls to it in H5O.c with HDtime()calls.

- Removed unused and misleading H5_timer_reset() function.  H5_timer_begin() resets the timer so there is no need for this.

- Added support for HDclock_gettime() as a clock_gettime() wrapper so we can implement monotonic clocks.  Windows has an empty framework but it is not implemented yet.

- Added an almost complete H5_timer_print() function to pretty print times.

- Added stubs for new begin and end functions.  The existing functions will be left in place until refactoring is complete.

- Added a new timer struct.

- Added a Windows-specific Wget_process_times() function to implement some of the getrusage() functionality.  It's not entirely clear how this will be exposed since a generic HDgetrusage() function would be too complicated to implement fully on non-Posix systems.

- Cleaned up some other minor things: comment blocks, tab/space cleanup and parenthesized the big if/else block in the bandwidth function.