Replaced nsecs with fractional seconds in units of seconds.
Replaced nsecs and secs members with public function members.
time_spec_t has a more diverse set of constructors and methods.
It can handle the cases where frac secs are greater than 1 second.
No longer part of the dude/bro protocol.
Simplified the mac and ip addr read write code in mboard impl.
Modified the mac addr type to take byte_vector_t from serial.hpp types.
And created utility functions to go between representations.
Created to_pp_string for pretty print strings for dboard ids and device addrs.
Minor changes to the various classes that call these utilities.
a zero length command (now, no chain) used to stop the streaming.
Now it seems to do the reverse... must investigate.
Made all clock configuration into enums. The strings were painful
and there cant be that many variations that enums cant cover them.
The enums will make more sense to developers than mystery strings.
Created structs to replace range tuples, and clock config struct.
Merged clock config props into one property using config struct.
Added templated dict construction to use the assign::map_list_of.
Added gcc flag to set visibility to hidden and use the api macro.
