Compatibility: delay() should call yield()

[dok-net]

In official AVR Arduino core, delay() is based on yield(), which is turn has weak binding and is overridable.
I am asking that delay() on any Arduino platform must call yield() at least once, preferably at the end of delay(), for compatibility with libraries like Scheduler and similar implementations.

[cmaglie]

Good suggestion, but yield must be called inside the busy loop not at the end of delay (there is no point in blocking until the end of the delay).

[dok-net]

PR #58 gets serious on this issue :-)