Add hal::time_limit to steady_clock.hpp

[kammce]

time_limit is almost exactly like timeout but it doesn't throw an exception. It returns a bool. Timeouts in libhal are categorized as error situations. Such functions should never throw an exception unless a critical time limit has been exceeded. With time_limit the assumption is that the limit being exceeded is apart of the logic and correct behavior. The callable's signature should look like and be compatible with:

using time_limit = bool(void);

Unlike timeout this doesn't need to be a concept. At least not util it is clear that such a construct is in demand. This should be a simple functor or lambda that uses a steady clock in order to determine if a time has expired.

There should also be a delay() api that delays until the remaining time has elapsed.