Improvements for Stream.cpp in methods "parseInt" and "parseFloat"

[fcebron]

I have noticed that the 2 methods "parseInt" and "parseFloat" in the Stream.cpp file which returns "0" when they reach a timeout. My problem with this is that I wanted to parse a String and find numbers (including zeros!) and to easily get read of characters which are not numbers.

To solve this, I suggest that these methods returns "(int)NAN" or "(float)NAN" in case that they reaches a timeout.

[cousteaulecommandant]

There's no such thing as (int)NAN though. Closest thing I can think of is LONG_MIN (-0x80000000), which is an unlikely value.

Maybe a better way around would be to add an optional parameter int *successful which "returns" 1 on success and 0 on error (similar to what strtol() does), or make additional parseInt_check and parseFloat_check functions that "return" the result in a pointed-to parameter and return 1 or 0 depending on their success status (similar to what scanf() does).

[Ben-Rheinland]

This is related to issue #70.

[ScruffR]

This is also related to arduino/Arduino#7177